Green B. Fundamentals of Chemistry 2007

Table of Contents

1. Periodic Table

2. Alkali Metals

3. Atoms and Molecules

4. Water

5. Organic Molecules

6. Dictionary

General Periodic Table 1 2 3 4 5 6 7 8 9 10 11 12

H 1 Hydrogen

Li Be 2 Lithium Beryllium Na Mg 3

Sodium Magnesium

A

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn 4 Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd 5 Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium

Cs Ba * Hf Ta W Re Os Ir Pt Au Hg 6 Cesium Barium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury T

Fr Ra ** Rf Db Sg Bh Hs Mt Uun Uuu Uub 7 Francium Radium Unnilquadium Unnilpentium Unnilhexium Unnilseptium Unniloctium Unnilennium Ununnilium Unununium Ununbium

* La Ce Pr Nd Pm Sm Eu Gd Tb Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dy

** Ac Th Pa U Np Pu Am Cm Bk

Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Ca

Element Groups (Families) Alkali Earth Alkaline Earth Transition MetalsRare Earth Other Metals Metalloids Non-Metals Halogens Noble Gases

Name wise Periodic Table

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18H He1 1

2

Li Be B C N O F Ne2 3 4 5 6 7 8 9 10

Na Mg Al Si P S Cl Ar3 11 12

13 14 15 16 17 18K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr4 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe5 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn6 55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86Fr Ra ** Rf Db Sg Bh Hs Mt Uun Uuu Uub7 87 88 104 105 106 107 108 109 110 111 112

* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71

** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

89 90 91 92 93 94 95 96 97 98 99 100 101 102 103

Element Groups (Families)

Alkali Earth Alkaline Eart

Transition Meta

h ls

Rare Earth

Other Metals

Metalloids

Non-Metals Halogens

Noble Gases

1 2 3 4 5 6 7 8 9 10 11

12

13

14

15

16 17

18

H He 1 1.00794

4.002602

Li Be B C N O F Ne 2

6.941 9.012182

10.811

12.0107

14.00674

15.9994

18.9984032

20.1797

Na Mg Al Si P S Cl Ar 3 22.98

9770 24.3050

26.98153

8 28.0855

30.97376

1 32.066

35.4527

39.948

K Ca Sc Ti V Cr Mn

Fe Co

Ni Cu Zn Ga Ge As Se Br Kr 4

39.0983

40.078

44.95591

0 47.867

50.9415

51.9961

54.93804

9 55.845

58.93320

0 58.6934

63.546

65.39

69.723

72.61

74.92160

78.96

79.904

83.80

Rb Sr Y Zr Nb Mo Tc

Ru Rh

Pd Ag Cd In Sn Sb Te I Xe 5

85.4678

87.62

88.90585

91.224

92.90638

95.94 (98)

101.07

102.9055

0 106.42

107.8682

112.411

114.818

118.710

121.760

127.60

126.90447

131.29

Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 6

132.90545

137.327

178.49

180.9479

183.84

186.207

190.23

192.217

195.078

196.9665

5 200.59

204.3833

207.2

208.9803

8 (209) (210) (222)

Fr Ra ** Rf Db Sg Bh

Hs Mt

Uun

Uuu

Uub 7

(223) (226)

(261)

(262) (263) (262)

(265) (266)

(269) (272) (277)

* La Ce Pr Nd Pm

Sm

Eu Gd Tb Dy Ho Er

Tm Yb Lu

138.9055

140.116

140.9076

5 144.24

(145)

150.36

151.964

157.25

158.9253

4 162.50

164.9303

2 167.26

168.9342

1 173.0

4 174.967

** Ac Th Pa U

Np Pu

Am

Cm Bk Cf Es

Fm

Md No Lr

(227) 232.0381

231.0358

8 238.0289

(237) (244)

(243) (247) (247) (251) (252) (257) (258) (259) (262)


Alkali Earth

Alkaline Earth

Transition Metals

Rare Earth

Other Metals

Metalloids

Non-Metals Halogens Noble Gases

1 2 3 4 5 6 7 8 9 1011

12

13

14

15

16

17

18

H He 11

2

Li Be B C N O F Ne 22,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8

Na Mg Al Si P S Cl Ar 32,8,1 2,8,2

2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 4

2,8,8,1

2,8,8,2

2,8,9,2

2,8,10,2

2,8,11,2

2,8,13,1

2,8,13,2

2,8,14,2

2,8,15,2

2,8,16,2

2,8,18,1

2,8,18,2

2,8,18,3

2,8,18,4

2,8,18,5

2,8,18,6

2,8,18,7

2,8,18,8

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd

Ag Cd In Sn Sb Te I Xe 5

2,8,18

8,1 2,8,1

8 8,2

2,8,18 9,2

2,8,18

10,2 2,8,1

8 12,1

2,8,18

13,1 2,8,1

8 14,1

2,8,18

15,1

2,8,18

16,1

2,8,18

18,0

2,8,18

18,1

2,8,18

18,2

2,8,18

18,3

2,8,18

18,4

2,8,18

18,5

2,8,18

18,6

2,8,18

18,7 2,8,1

8 18,8

Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 62,8,1

8 18,8,

1

2,8,18

18,8,2

2,8,1

8 32,10,2

2,8,18

32,11,2

2,8,18

32,12,2

2,8,18

32,13,2

2,8,18

32,14,2

2,8,18

32,15,2

2,8,18

32,17,1

2,8,18

32,18,1

2,8,18

32,18,2

2,8,18

32,18,3

2,8,18

32,18,4

2,8,18

32,18,5

2,8,18

32,18,6

2,8,18

32,18,7

2,8,18

32,18,8

Fr Ra ** Rf Db Sg Bh Hs Mt

Uun

Uuu

Uub

72,8,18,32 18,8,

1

2,8,18,32 18,8,

2

2,8,18,32 32,10,2

2,8,18,32 32,11,2

2,8,18,32 32,12,2

2,8,18,32 32,13,2

2,8,18,3232,14,2

2,8,18,3232,15,2

2,8,18,3232,17,1

2,8,18,3232,18,1

2,8,18,3232,18,2

* La Ce Pr Nd Pm

Sm Eu

Gd Tb

Dy

Ho Er

Tm

Yb Lu

2,8,1

8 18,9,

2

2,8,18

20,8,2

2,8,18

21,8,2

2,8,18

22,8,2

2,8,18

23,8,2

2,8,18

24,8,2

2,8,18

25,8,2

2,8,18

25,9,2

2,8,18

27,8,2

2,8,18

28,8,2

2,8,18

29,8,2

2,8,18

30,8,2

2,8,18

31,8,2

2,8,18

32,8,2

2,8,18

32,9,2

** Ac Th Pa U

Np Pu

Am

Cm Bk Cf Es

Fm

Md

No Lr

2,8,18,32 18,9,

2

2,8,18,32 18,10,2

2,8,18,32 20,9,

2

2,8,18,32 21,9,

2

2,8,18,3223,8,

2

2,8,18,3224,8,

2

2,8,18,3225,8,

2

2,8,18,3225,9,

2

2,8,18,3226,9,

2

2,8,18,3228,8,

2

2,8,18,3229,8,

2

2,8,18,3230,8,

2

2,8,18,3231,8,

2

2,8,18,32 32,8,

2

2,8,18,32 32,9,

2


Alkali Earth Alkaline Earth

Transition Metals

Rare Earth Other Metals Metalloids


1 2 3 4 5 6 7 8 9 10 11 12 1314

15

16

17 18

H He 10

2

Li Be B C N O F Ne 24 5 6 6 7 8 10 10 Na

Mg Al Si P S Cl Ar 3

12 12

14 14 16 16 18 22

K Ca Sc Ti V Cr

Mn Fe

Co Ni Cu Zn

Ga

Ge

As Se Br Kr 4

20 20 24 26 28 28 30 30 32 31 35 35 39 41 42 45 45 48 Rb Sr Y

Zr

Nb

Mo Tc

Ru

Rh Pd Ag Cd In

Sn

Sb Te I Xe 5

48 50 50 51 52 54 55 57 58 60 61 64 66 69 71 76 74 77 Cs

Ba *

Hf

Ta W

Re

Os Ir Pt Au Hg Tl

Pb Bi Po At Rn 6

78 81 106 108 110 111 114 115 117 118 121 123 125 126 125 125 136

Fr Ra **

Rf

Db Sg

Bh

Hs

Mt

Uun

Uuu

Uub 7

136 138 157 157 157 155 157 157 159 161 165

* La Ce Pr

Nd

Pm

Sm Eu Gd Tb

Dy

Ho Er

Tm

Yb Lu

82 82 82 84 84 88 89 93 94 97 98 99 100 103 104

**

Ac

Th Pa U

Np

Pu

Am

Cm Bk Cf Es

Fm

Md

No Lr

138 142 140 146 144 150 148 151 150 153 153 157 157 157 159



Transition Metals



1 2 3 4 5 6 7 8 9 10 1112

13

14

15

16

17 18

H He 1 -

259.14

-272

Li Be B C N O F Ne 2180.54

1278

2300 3500 -

209.9

-218.

4 -

219.62

-248.6

Na


97.8 650

660.37

1410 44.1

112.8

-100.98

-189.3

K Ca Sc

Ti V Cr

Mn Fe

Co Ni Cu Zn

Ga

Ge

As Se Br Kr 4

63.65 839

1539

1660

1890

1857

1245

1535

1495 1453 1083

419.58

29.78

937.4 817 217 -7.2 -157.2

Rb Sr Y

Zr

Nb

Mo

Tc

Ru

Rh Pd Ag Cd In

Sn

Sb

Te I Xe 5

38.89 764

1523

1852

2468

2617

2200

2250

1966 1552

961.93 320.9

156.61

231.9 630

449.5

113.5 -111.9

Cs Ba * Hf

Ta W

Re

Os Ir Pt Au Hg Tl

Pb Bi

Po At Rn 6

28.5 725 2150 2996

3410

3180

3045

2410 1772

1064.43

-38.87

303.5

327.5

271.3 254 302 -71

Fr Ra **

Rf

Db

Sg

Bh

Hs

Mt

Uun

Uuu

Uub 7

27 700 ? ? ? ? ? ? ? ? ?

* La Ce Pr

Nd

Pm

Sm Eu Gd Tb

Dy

Ho Er

Tm

Yb Lu

920 795 935 1010 ? 1072 822 1311 1360 1412

1470

1522

1545 824 1656

**

Ac

Th Pa U

Np

Pu

Am

Cm Bk Cf Es

Fm

Md

No Lr

1050 1750

1600

1132 640

639.5 994 1340 ? ? ? ? ? ? ?



Transition Metals



1 2 3 4 5 6 7 8 9 10 11

12

13

14

15

16

17 18

H He

H He 1 -

252.87

-268.6

Li Be B C N O F Ne 21347 2970

2550

4827

-195.

8 -183

-188.14

-246.1

Na


552.9

1107

2467

2355 280

444.6 -34.6 -186

K Ca Sc

Ti V Cr

Mn Fe

Co Ni Cu Zn

Ga

Ge

As Se Br Kr 4

774 1484 2832

3287

3380

2672

1962

2750

2870 2732 2567 907

2403

2830 613

684.9

58.78 -153.4

Rb Sr Y

Zr

Nb

Mo Tc

Ru

Rh Pd Ag Cd In

Sn

Sb Te I Xe 5

688 1384 3337

4377

4927

4612

4877

3900

3727 2927 2212 765

2000

2270

1750

989.8 184 -108.1

Cs Ba * Hf

Ta W

Re

Os Ir Pt Au Hg Tl

Pb Bi Po At Rn 6

678.4

1140

5400

5425

5660

5627

5027

4527 3827 2807

356.58

1457

1740

1560 962 337 -61.8

Fr Ra **

Rf

Db Sg

Bh

Hs

Mt

Uun

Uuu

Uub 7

677 1737 ? ? ? ? ? ? ? ? ?

* La Ce Pr

Nd

Pm

Sm Eu Gd Tb

Dy

Ho Er

Tm

Yb Lu

3469 3257

3127

3127 ?

1900 1597 3233 3041

2562

2720

2510

1727 1466 3315

**

Ac

Th Pa U

Np

Pu

Am

Cm Bk Cf Es

Fm

Md

No Lr

3200 4790 ?

3818

3902

3235 2607 ? ? ? ? ? ? ? ?

Element Groups (Families) Alkali Earth Alkaline Earth Transition MetalsRare Earth Other Metals Metalloids Non-Metals Halogens Noble Gases

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18H He1 Hex

Hex

Li Be B C N O F Ne2 Cub Hex Rhom Hex Hex Cub Cub CubNa Mg Al Si P S Cl Ar3 Cub Hex

Cub Cub Mono Ortho Ortho CubK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr4 Cub Cub Hex Hex Cub Cub Cub Cub Hex Cub Cub Hex Ortho Cub Rhom Hex Ortho CubRb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe5 Cub Cub Hex Hex Cub Cub Hex Hex Cub Cub Cub Hex Tet Tet Rhom Hex Ortho CubCs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn6 Cub Cub Hex Cub Cub Hex Hex Cub Cub Cub Rhom Hex Cub Rhom Mono ? Cub

Fr Ra ** Rf Db Sg Bh Hs Mt Uun Uuu Uub7 Cub Cub ? ? ? ? ? ? ? ? ?

* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hex Cub Hex Hex Hex Rhom Cub Hex Hex Hex Hex Hex Hex Cub Hex

** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Cub Cub Ortho Ortho Ortho Mono Hex ? ? ? ? ? ? ? ?

Crystal Structure AbbreviationsHex Hexagonal Rhom Rhombohedral Cub Cubic Mono Monoclinic Ortho Orthorhombic Tet Tetragonal ? Unknown

Element Groups (Families) Alkali Earth Alkaline Earth Transition Metals Rare Earth Other Metals Metalloids Non-Metals Halogens Noble Gases

Alkali Metals The alkali metals, found in group 1 of the periodic table (formerly known as group IA), are very reactive metals that do not occur freely in nature. These metals have only one electron in their outer shell. Therefore, they are ready to lose that one electron in ionic bonding with other elements. As with all metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity. The alkali metals are softer than most other metals. Cesium and francium are the most reactive elements in this group. Alkali metals can explode if they are exposed to water.

The Alkali Metals are:

Lithium Sodium Potassium Rubidium Cesium Francium

Basic Information

Name: Lithium Symbol: Li Atomic Number: 3 Atomic Mass: 6.941 amu Melting Point: 180.54 C (453.69 K, 356.972 F) Boiling Point: 1347.0 C (1620.15 K, 2456.6 F) Number of Protons/Electrons: 3 Number of Neutrons: 4 Classification: Alkali Metal Crystal Structure: Cubic Density @ 293 K: 0.53 g/cm3 Color: silvery

Atomic Structure

Number of Energy Levels: 2

First Energy Level: 2 Second Energy Level: 1

Isotopes

Isotope Half Life Li-6 Stable Li-7 Stable

Facts

Date of Discovery: 1817 Discoverer: Johann Arfvedson Name Origin: From the Greek word lithos (stone) Uses: batteries, ceramics, lubricants Obtained From: passing electric charge through melted lithium chloride, spodumene Name: Sodium Symbol: Na Atomic Number: 11 Atomic Mass: 22.98977 amu Melting Point: 97.8 C (370.95 K, 208.04001 F) Boiling Point: 552.9 C (826.05005 K, 1027.2201 F) Number of Protons/Electrons: 11 Number of Neutrons: 12 Classification: Alkali Metal Crystal Structure: Cubic

Density @ 293 K: 0.971 g/cm3 Color: silvery

Atomic Structure


First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 1

Isotopes

Isotope Half Life Na-22 2.6 years Na-23 Stable Na-24 14.96 hours

Facts

Date of Discovery: 1807 Discoverer: Sir Humphrey Davy Name Origin: soda (Na2CO3) Symbol Origin: From the Latin word natrium (sodium) Uses: medicine, agriculture Obtained From: table salts and other foods Name: Potassium Symbol: K Atomic Number: 19 Atomic Mass: 39.0983 amu Melting Point: 63.65 C (336.8 K, 146.57 F)

Boiling Point: 774.0 C (1047.15 K, 1425.2 F) Number of Protons/Electrons: 19 Number of Neutrons: 20 Classification: Alkali Metal Crystal Structure: Cubic Density @ 293 K: 0.862 g/cm3 Color: silvery

Atomic Structure


First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 8 Fourth Energy Level: 1

Isotopes

Isotope Half Life K-39 Stable K-40 1.28E9 years K-41 Stable K-42 12.4 hours K-43 22.3 hours

Facts

Date of Discovery: 1807 Discoverer: Sir Humphrey Davy Name Origin: potash

Symbol Origin: From the Latin word kalium Uses: glass, soap Obtained From: minerals (carnallite) Name: Rubidium Symbol: Rb Atomic Number: 37 Atomic Mass: 85.4678 amu Melting Point: 38.89 C (312.04 K, 102.002 F) Boiling Point: 688.0 C (961.15 K, 1270.4 F) Number of Protons/Electrons: 37 Number of Neutrons: 48 Classification: Alkali Metal Crystal Structure: Cubic Density @ 293 K: 1.532 g/cm3 Color: silver

Atomic Structure


First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 8 Fifth Energy Level: 1

Isotopes

Isotope Half Life Rb-81 4.57 hours Rb-82 2.25 minutes Rb-83 86.2 days Rb-84 32.9 days Rb-85 Stable

Rb-86 18.65 days Rb-87 4.8E10 years Rb-88 17.7 minutes Rb-89 15.44 minutes Rb-90 2.6 minutes Rb-90m 4.3 minutes

Facts

Date of Discovery: 1861 Discoverer: R. Bunsen Name Origin: From the Latin word rubidus (red) Uses: catalyst, photocells Obtained From: lithium production Name: Cesium Symbol: Cs Atomic Number: 55 Atomic Mass: 132.90546 amu Melting Point: 28.5 C (301.65 K, 83.3 F) Boiling Point: 678.4 C (951.55005 K, 1253.12 F) Number of Protons/Electrons: 55 Number of Neutrons: 78 Classification: Alkali Metal Crystal Structure: Cubic Density @ 293 K: 1.873 g/cm3 Color: silver British Spelling: Caesium IUPAC Spelling: Caesium

Atomic Structure


First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 18 Fifth Energy Level: 8 Sixth Energy Level: 1

Isotopes

Isotope Half Life Cs-126 1.6 minutes Cs-129 1.3 days Cs-131 9.7 days Cs-132 6.4 days Cs-133 Stable Cs-134 2.1 years Cs-134m 2.9 hours

Cs-135 2300000.0 years Cs-136 13.2 days Cs-137 30.2 years Cs-138 32.2 minutes Cs-139 9.3 minutes

Facts

Date of Discovery: 1860 Discoverer: Fustov Kirchoff Name Origin: From the Latin word caesius (sky blue) Uses: remosves air traces in vacuum tubes Obtained From: pollucite, lepidolite

ATOMS AND MOLECULES Atoms

Most of the Universe consists of matter and energy. Energy is the capacity to do work. Matter has mass and occupies space. All matter is composed of basic elements that cannot be broken down to substances with different chemical or physical properties. Elements are substances consisting of one type of atom, for example Carbon atoms make up diamond, and also graphite. Pure (24K) gold is composed of only one type of atom, gold atoms. Atoms are the smallest particle into which an element can be divided. The ancient Greek philosophers developed the concept of the atom, although they considered it the fundamental particle that could not be broken down. Since the work of Enrico Fermi and his colleagues, we now know that the atom is divisible, often releasing tremendous energies as in nuclear explosions or (in a controlled fashion in) thermonuclear power plants.

Subatomic particles were discovered during the 1800s. For our purposes we will concentrate only on three of them. The proton is located in the center (or nucleus) of an atom, each atom has at least one proton. Protons have a charge of +1, and a mass of approximately 1 atomic mass unit (amu). Elements differ from each other in the number of protons they have, e.g. Hydrogen has 1 proton; Helium has 2.

The neutron also is located in the atomic nucleus (except in Hydrogen). The neutron has no charge, and a mass of slightly over 1 amu. Some scientists propose the neutron is made up of a proton and electron-like particle.

The electron is a very small particle located outside the nucleus. Because they move at speeds near the speed of light the precise location of electrons is hard to pin down. Electrons occupy orbitals, or areas where they have a high statistical probability of occurring. The charge on an electron is -1. Its mass is negligible (approximately 1800 electrons are needed to equal the mass of one proton).

The atomic number is the number of protons an atom has. It is characteristic and unique for each element. The atomic mass (also referred to as the atomic

weight) is the number of protons and neutrons in an atom. Atoms of an element that have differing numbers of neutrons (but a constant atomic number) are termed isotopes. Isotopes can be used to determine the diet of ancient peoples by determining proportions of isotopes in mummified or fossilized human tissues. Biochemical pathways can be deciphered by using isotopic tracers. The age of fossils and artifacts can be determined by using radioactive isotopes, either directly on the fossil (if it is young enough) or on the rocks that surround the fossil 9for older fossils like dinosaurs). Isotopes are also the source of radiation used in medical diagnostic and treatment procedures.

Note that each of these isotopes of hydrogen has only one proton. Isotopes differ from each other in the number of neutrons, not in the number of protons. Some isotopes are radioisotopes, which spontaneously decay, releasing radioactivity. Other isotopes are stable. Examples of radioisotopes are Carbon-14 (symbol 14C), and deuterium (also known as Hydrogen-2; 2H). Stable isotopes are 12C and 1H.

Carbon has three isotopes, of which carbon-12 and carbon-14 are the most well known.

The Periodic Table of the Elements. Each Roman numeraled column on the label (at least the ones ending in A) tells us how many electrons are in the outer shell of the atom. Each numbered row on the table tells us how many electron shells an atom has. Thus, Hydrogen, in column IA, row 1 has one electron in one shell. Phosphorous in column VA, row 3 has 5 electrons in its outer shell, and has three shells in total.

Electro

ns and energy

Electrons, because they move so fast (approximately at the speed of light), seem to straddle the fence separating energy from matter. Because of this, we think of electrons both as particles of matter (having mass is a property of matter) and as units (or quanta) of energy. When subjected to energy, electrons will acquire some of that energy.

Excitation of an electron by energy, causing the electron to "jump" to another electron (energy) level known as the excited state.

An orbital is also an area of space in which an electron will be found 90% of the time. Orbitals are of different shapes. Each orbital has a characteristic energy state and a characteristic shape. The s orbital is spherical, and located closest to the nucleus. Since each orbital can hold a maximum of two electrons, atomic numbers above 2 must fill the other orbitals. The px, py, and pz orbitals are dumbbell shaped, along the x, y, and z axes respectively. The major energy levels (also known as shells) into which electrons fit, are (from the nucleus outward) K, L, M, and N. Sometimes these are numbered, with electron configurations being: 1s22s22p1, etc. This nomenclature tells us the 1st energy level (shell) has 2 electrons in the s orbital, and 2nd energy level has 2 electrons in its s orbital, plus one electron in its p orbital.

Geometry of orbitals. S-orbitals are spherical, p-orbitals are shaped like a dumbbell

Chemical Bonding

During the nineteenth century, chemists arranged the then-known elements according to chemical bonding, recognizing that one group (the furthermost right column on the Periodic Table, referred to as the Inert Gases or Noble Gases) tended to occur in elemental form (in other words, not in a molecule with other elements). It was later determined that this group had outer electron shells containing two (as in the case of Helium) or eight (Neon, Xenon, Radon, Krypton, etc.) electrons.

As a general rule, for the atoms we are likely to encounter in biological systems, atoms tend to gain or lose their outer electrons to achieve a Noble Gas outer electron shell configuration of 2 or 8 electrons. The number of electrons that are gained or lost is characteristic for each element, and ultimately determines the number and types of chemical bonds atoms of that element can form.

Atomic diagrams illustrating the filling of the outer electron shells.

Ionic bonds are formed when atoms become ions by gaining or losing electrons. Chlorine is in a group of elements having seven electrons in their outer shells. Members of this group tend to gain one electron, acquiring a charge of -1. Sodium is in another group with elements having one electron in

their outer shells. Members of this group tend to lose that outer electron, acquiring a charge of +1. Oppositely charged ions are attracted to each other, thus Cl- (the symbolic representation of chlorine) and Na+ (the symbol for sodium, using the Greek word natrium) form an ionic bond, becoming the molecule sodium chloride. Ionic bonds generally form between elements in Group I (having one electron in their outer shell) and Group VIIa (having seven electrons in their outer shell). Such bonds are relatively weak, and tend to disassociate in water, producing solutions that have both Na and Cl ions.

Formation of a crystal of sodium chloride. Each positively charged sodium ion is surropunded by six negatively charged chloride ions; likewise each negatively charged chloride ion is surrounded by six positively charged sodium ions. The overall effect is electrical neutrality.

Table Salt Crystal (SEM x625).

Covalent bonds form when atoms share electrons. Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond. Such bonds are referred to as electron-sharing bonds. An analogy can be made to child custody: the children are like electrons, and tend to spend some time with one parent and the rest of their time with the other parent. In a covalent bond, the electron clouds surrounding the atomic nuclei overlap.

Formation of a covalent bond between two Hydrogen atoims.

Carbon (C) is in Group IVa, meaning it has 4 electrons in its outer shell. Thus to become a "happy atom", Carbon can either gain or lose four electrons. By sharing the electrons with other atoms, Carbon can become a happy atom,. alternately filling and emptying its outer shell.

Formation of covalent bonds in methane. Carbon needs to share four electrons, in effect it has four slots. Each hydrogen provides an electron to each of these slots. At the same time each hydrogen needs to fill one slot, which is done by sharing an electron with the carbon.

The molecule methane (chemical formula CH4) has four covalent bonds, one between Carbon and each of the four Hydrogens. Carbon contributes an electron, and Hydrogen contributes an electron. The sharing of a single electron pair is termed a single bond. When two pairs of electrons are shared, a double bond results, as in carbon dioxide. Triple bonds are known, wherein three pairs (six electrons total) are shared as in acetylene gas or nitrogen gas.

Ways of representing covalent bonds.

Sometimes electrons tend to spend more time with one atom than with another. In such cases a polar covalent bond develops. Water (H2O) is an example. Since the electrons spend so much time with the oxygen (oxygen having a greater electronegativity, or electron affinity) that end of the molecule acquires a slightly negative charge. Conversely, the loss of the electrons from the hydrogen end leaves a slightly positive charge. The water molecule is thus polar, having positive and negative sides.

Hydrogen bonds result from the weak electrical attraction between the positive end of one molecule and the negative end of another. Individually these bonds are very weak, although taken in a large enough quantity, the result is strong enough to hold molecules together or in a three-dimensional shape.

Formation of a hydrogen bond between the hydrogen side of one water molecule and the oxygen side of another water molecule.

The presence of polar areas in the amino acids that makeup a protein allows for hydrogen bonds to form, giving the molecule a three-dimensional shape that is often vital to that protein's proper functioning.

Chemical reactions and molecules

Molecule versus Mixture: Molecules are compounds with elements in definite, fixed ratios. Those atoms are held together usually by one of the three bonds discussed above. For example: water, glucose, ATP. Mixtures are compounds

with variable formulas/ratios of their components. For example: soil. Molecular formulas are an expression in the simplest whole-number terms of the composition of a substance. For example, the sugar glucose has 6 Carbons, 12 hydrogens, and 6 oxygens per repeating structural unit. The formula is written C6H12O6.

Determination of molecular weights by addition of the weights of the atoms that make up the molecule.

Chemical reactions occur in nature, and somse also can be performed in a laboratory setting. Chemical Equations are linear representations of how these reactions occur. Combination reactions occur when two separate reactants are bonded together, e.g. A + B -----> AB. Disassociation reactions; occur when a compound is broken into two products, e.g. AB -----> A + B.

Diagram of a chemical reaction: the combustion of propane with oxygen, resulting in carbon dioxide, water, and energy (as heat and light). This chemical reaction takes place in a camping stove as well as in certain welding torches.

Biological systems, while unique to each species, are based on the chemical bonding properties of carbon. Major organic chemicals (those associated with or formed by the actions of living things) usually include some ratios of the following elements: C, H, N, O, P, S.

Learning Objectives All forms of matter are composed of one or more elements. Be able to list the

major elements in living things. Describe how protons, electrons, and neutrons are arranged into atoms and ions. Define the terms atomic number and atomic mass and be able to describe their

sugnificance. Atoms with the same atomic number but a different mass number are isotopes.

List the isotopes of hydrogen and of carbon. Be able to describe radioisotopes and list three ways they are used in biology. The union between the electron structures of atoms is known as the chemical

bond. Be able to list and describe the three types of chemical bonds found in living things.

Be able to describe the distribution of electrons in the space around the nucleus of an atom.

An atom tends to react with other atoms when its outermost shell is only partly filled with electrons. Be able to discuss why this happens.

Be able to define the two types of ions and describe thow ionic bonds form between positive and negative ions.

In a covalent bond, atoms share electrons. List several elements that tend to form covalent bonds.

Distinguish between a nonpolar covalent bond and a polar covalent bond and give an example of each.

Define hydrogen bond and describe conditions under which hydrogen bonds form and cite one example.

Explain what is meant by the polarity of the water molecule, and how the polarity of water molecules allows them to interact with one another.

WATER Structure of Water

It can be quite correctly argued that life exists on Earth because of the abundant liquid water. Other planets have water, but they either have it as a gas (Venus) or ice (Mars). Recent studies of mars reveal the presence sometime in the past of running fluid, possibly water. The chemical nature of water is thus one we must examine as it permeates living systems: water is a universal solvent, and can be too much of a good thing for some cells to deal with.

Water can exist in all three states of matter on Earth, while only in one state on our two nearest neighboring planets.

Water is polar covalently bonded within the molecule. This unequal sharing of the electrons results in a slightly positive and a slightly negative side of the

molecule. Other molecules, such as Ethane, are nonpolar, having neither a positive nor a negative side.

The difference between a polar (water) and nonpolar (ethane) molecule is due to the unequal sharing of electrons within the polar molecule. Nonpolar molecules have electrons equally shared within their covalent bonds.

Consequently, water has a great interconnectivity of individual molecules, which is caused by the individually weak hydrogen bonds that can be quite strong when taken by the billions.

Formation of a hydrogen bond between the hydrogen side of one water molecule and the oxygen side of another water molecule.

Water has been referred to as the universal solvent. Living things are composed of atoms and molecules within aqueous solutions (solutions that have materials dissolved in water). Solutions are uniform mixtures of the molecules of two or more substances. The solvent is usually the substance present in the greatest amount (and is usually also a liquid). The substances of lesser amounts are the solutes.

Dissolution of an ionically bonded compound, sodium chloride, by water molecules.

The solubility of many molecules is determined by their molecular structure. You are familiar with the phrase "mixing like oil and water." The biochemical basis for this phrase is that the organic macromolecules known as lipids (of which fats are an important, although often troublesome, group) have areas that lack polar covalent bonds. The polar covalently bonded water molecules act to exclude nonpolar molecules, causing the fats to clump together. The structure of many molecules can greatly influence their solubility. Sugars, such as glucose, have many hydroxyl (OH) groups, which tend to increase the solubility of the molecule.

Water tends to disassociate into H+ and OH- ions. In this disassociation, the oxygen retains the electrons and only one of the hydrogens, becoming a negatively charged ion known as hydroxide. Pure water has the same number (or concentration) of H+ as OH- ions. Acidic solutions have more H+ ions than OH- ions. Basic solutions have the opposite. An acid causes an increase in the numbers of H+ ions and a base causes an increase in the numbers of OH- ions.

pH of some common items.

The pH scale is a logarithmic scale representing the concentration of H+ ions in a solution. Remember that as the H+ concentration increases the OH- concentration decreases and vice versa . If we have a solution with one in every ten molecules being H+, we refer to the concentration of H+ ions as 1/10. Remember from algebra that we can write a fraction as a negative exponent, thus 1/10 becomes 10-1. Conversely 1/100 becomes 10-2 , 1/1000 becomes 10-3, etc. Logarithms are exponents to which a number (usually 10) has been raised. For example log 10 (pronounced "the log of 10") = 1 (since 10 may be written as 101). The log 1/10 (or 10-1) = -1. pH, a measure of the concentration of H+

ions, is the negative log of the H+ ion concentration. If the pH of water is 7, then the concentration of H+ ions is 10-7, or 1/10,000,000. In the case of strong acids, such as hydrochloric acid (HCl), an acid secreted by the lining of your stomach, [H+] (the concentration of H+ ions, written in a chemical shorthand) is 10-1; therefore the pH is 1.

Organic molecules

Organic molecules are those that: 1) formed by the actions of living things; and/or 2) have a carbon backbone. Methane (CH4) is an example of this. If we remove the H from one of the methane units below, and begin linking them up, while removing other H units, we begin to form an organic molecule. (NOTE: Not all methane is organically derived, methane is a major component of the atmosphere of Jupiter, which we think is devoid of life). When two methanes are combined, the resultant molecule is Ethane, which has a chemical formula C2H6. Molecules made up of H and C are known as hydrocarbons.

Types of hydrocarbon compounds and their structure.

Scientists eventually realized that specific chemical properties were a result of the presence of particular functional groups. Functional groups are clusters of atoms with characteristic structure and functions. Polar molecules (with +/- charges) are attracted to water molecules and are hydrophilic. Nonpolar molecules are repelled by water and do not dissolve in water; are hydrophobic. Hydrocarbon is hydrophobic except when it has an attached ionized functional group such as carboxyl (acid) (COOH), then molecule is hydrophilic. Since cells are 70-90% water, the degree to which organic molecules interact with water affects their function. One of the most common groups is the -OH (hydroxyl) group. Its presence will enable a molecule to be water soluble.

Isomers are molecules with identical molecular formulas but differ in arrangement of their atoms (e.g., glyceraldehyde and dihydroxyacetone).

Functional groups in organic molecules.

Carbon has four electrons in outer shell, and can bond with up to four other atoms (usually H, O, N, or another C). Since carbon can make covalent bonds with another carbon atom, carbon chains and rings that serve as the backbones of organic molecules are possible.

Chemical bonds store energy. The C-C covalent bond has 83.1 Kcal (kilocalories) per mole, while the C=C double covalent bond has 147 Kcal/mole. Energy is in two forms: kinetic, or energy in use/motion; and potential, or energy at rest or in storage. Chemical bonds are potential energy, until they are converted into another form of energy, kinetic energy (according to the two laws of thermodynamics).

Each organic molecule group has small molecules (monomers) that are linked to form a larger organic molecule (macromolecule). Monomers can be jouined together to form polymers that are the large macromolecules made of three to millions of monomer subunits.

Macromolecules are constructed by covalently bonding monomers by condensation reactions where water is removed from functional groups on the monomers. Cellular enzymes carry out condensation (and the reversal of the reaction, hydrolysis of polymers). Condensation involves a dehydration synthesis because a water is removed (dehydration) and a bond is made (synthesis). When two monomers join, a hydroxyl (OH) group is removed from one monomer and a hydrogen (H) is removed from the other. This produces the water given off during a condensation reaction. Hydrolysis (hydration) reactions break down polymers in reverse of condensation; a hydroxyl (OH) group from water attaches to one monomer and hydrogen (H) attaches to the other.

There are four classes of macromolecules (polysaccharides, triglycerides, polypeptides, nucleic acids). These classes perform a variety of functions in cells.

1. Carbohydrates have the general formula [CH2O]n where n is a number between 3 and 6. Note the different CH2O units on the diagram below.

Carbohydrates function in short-term energy storage (such as sugar); as intermediate-term energy storage (starch for plants and glycogen for animals); and as structural components in cells (cellulose in the cell walls of plants and many protists), and chitin in the exoskeleton of insects and other arthropods.

Sugars are structurally the simplest carbohydrates. They are the structural unit which makes up the other types of carbohydrates. Monosaccharides are single (mono=one) sugars. Important monosaccharides include ribose (C5H10O5), glucose (C6H12O6), and fructose (same formula but different structure than glucose).

The chain (left) and ring (center and right) method of representing carbohydrates.

Classification of monosaccharides is done by the number of carbon atoms and the types of functional groups. For example, glucose and fructose have the same chemical formula, but different structure: glucose having an aldehyde (internal hydroxyl shown as: -OH) and fructose having a keto group (internal double-bond O, shown as: =O).

Models of glucose and fructose.

In aqueous solution, glucose tends to have two structures, and , with an intermediate straight-chain form. The form and form differ in the location of one -OH group. Glucose is a common hexose in plants. The products of photosynthesis are assembled to make a glucose. Energy from sunlight is converted into the C-C covalent bond energy. This energy is released in living organisms in such a way that not enough heat is generated at once to incinerate the organisms. One mole of glucose yields 673 Kcal of energy. (A calorie is the amount of heat needed to raise one gram of water one degree C. A Kcal has 1000 times as much energy as a cal.)

D-Glucose in various views (stick and space-filling) from the web. Disaccharides are formed when two monosaccharides are chemically bonded together. Sucrose, a common plant disaccharide is composed of the monosaccharides glucose and fructose. Lactose, milk sugar, is a disaccharide composed of glucose and the monosaccharide galactose.

Formation of a disaccharide (top) by condensation and structure of two common disaccharides.

Polysaccharides are large molecules composed of individual monosaccharide units. A common plant polysaccharide is starch, which is made up of many glucoses (in a polypeptide these are referred to as glucans). Two forms of polysaccharide, amylose and amylopectin makeup what we commonly call starch. The formation of the ester bond by condensation (the removal of water from a molecule) allows the linking of monosaccharides into disaccharides and polysaccharides. Glycogen is an animal storage product that accumulates in the vertebrate liver.

Images of starch (top), glycogen (middle), and cellulose (bottom).

Cellulose is a polysaccharide found in plant cell walls. Cellulose forms the fibrous part of the plant cell wall. In terms of human diets, cellulose is indigestible, and thus forms an important, easily obtained part of dietary fiber. As compared to starch and glycogen, which are each made up of mixtures of and glucoses, cellulose (and the animal structural polysaccharide chitin) are made up of only glucoses. The three-dimensional structure of the structural polysaccharides is thus constrained into straight microfibrils by the uniform nature of the glucoses, which resist the actions of enzymes (such as amylase) that breakdown storage polysaccharides (such a starch).

Structure of cellulose as it occurs in a plant cell wall.

Cellulose Fibers from Print Paper (SEM x1,080).

2. Lipids are involved mainly with long-term energy storage. They are generally insoluble in polar substances such as water. Secondary functions of

lipids are as structural components (as in the case of phospholipids that are the major building block in cell membranes) and as "messengers" (hormones) that play roles in communications within and between cells. Lipids are composed of three fatty acids (usually) covalently bonded to a 3-carbon glycerol. The fatty acids are composed of CH2 units, and are hydrophobic/not water soluble.

Saturated (top and middle) and unsaturated (bottom) fatty acids. The term staurated refers to the "saturation" of the molecule by hydrogen atoms. The presence of a double C=C covalent bond reduces the number of hydrogens that can bond to the carbon chain, hence the application of therm "unsaturated".

Fatty acids can be saturated (meaning they have as many hydrogens bonded to their carbons as possible) or unsaturated (with one or more double bonds connecting their carbons, hence fewer hydrogens). A fat is solid at room

temperature, while an oil is a liquid under the same conditions. The fatty acids in oils are mostly unsaturated, while those in fats are mostly saturated.

Fats and oils function for in energy storage. Animals convert excess sugars (beyond their glycogen storage capacities) into fats. Most plants store excess sugars as starch, although some seeds and fruits have energy stored as oils (e.g. corn oil, peanut oil, palm oil, canola oil, and sunflower oil). Fats yield 9.3 Kcal/gm, while carbohydrates yield 3.79 Kcal/gm. Fats store six times as much energy as glycogen.

Diets are attempts to reduce the amount of fats present in specialized cells known as adipose cells that accumulate in certain areas of the human body. By restricting the intakes of carbohydrates and fats, the body is forced to draw on its own stores to makeup the energy debt. The body responds to this by lowering its metabolic rate, often resulting in a drop of "energy level." Successful diets usually involve three things: decreasing the amounts of carbohydrates and fats; exercise; and behavior modification.

Another use of fats is as insulators and cushions. The human body naturally accumulates some fats in the "posterior" area. Subdermal ("under the skin") fat plays a role in insulation.

Phospholipids and glycolipids are important structural components of cell membranes. Phospholipids are modified so that a phosphate group (PO4-) is added to one of the fatty acids. The addition of this group makes a polar "head" and two nonpolar "tails". Waxes are an important structural component for many organisms, such as the cuticle, a waxy layer covering the leaves and stems of many land plants; and protective coverings on skin and fur of animals.

Structure of a phospholipid, space-filling model (left) and chain model (right).

Cholesterol and steroids: Most mention of these two in the news is usually negative. Cholesterol has many biological uses, such as its occurrence in the cell membranes, and its role in forming the sheath of some neurons. Excess cholesterol in the blood has been linked to atherosclerosis, hardening of the arteries. Recent studies suggest a link between arterial plaque deposits of cholesterol, antibodies to the pneumonia-causing form of Chlamydia, and heart attacks. The plaque increases blood pressure, much the way blockages in plumbing cause burst pipes in old houses.

Structure of four steroids.

3. Proteins are very important in biological systems as control and structural elements. Control functions of proteins are carried out by enzymes and proteinaceous hormones. Enzymes are chemicals that act as organic catalysts (a catalyst is a chemical that promotes but is not changed by a chemical reaction). Click here for an illustrated page about enzymes. Structural proteins function in the cell membrane, muscle tissue, etc.

The building block of any protein is the amino acid, which has an amino end (NH2) and a carboxyl end (COOH). The R indicates the variable component (R-group) of each amino acid. Alanine and Valine, for example, are both nonpolar amino acids, but they differ, as do all amino acids, by the composition of their R-groups. All living things (and even viruses) use various combinations of the same twenty amino acids. A very powerful bit of evidence for the phylogenetic connection of all living things.

Structure of an amino acid.

Structures in the R-groups of the twenty amino acids found in all living things.

Amino acids are linked together by joining the amino end of one molecule to the carboxyl end of another. Removal of water allows formation of a type of covalent bond known as a peptide bond.

Formation of a peptide bond between two amino acids by the condensation (dehydration) of the amino end of one amino acid and the acid end of the other amino acid.

Amino acids are linked together into a polypeptide, the primary structure in the organization of proteins. The primary structure of a protein is the sequence of amino acids, which is directly related to the sequence of information in the RNA molecule, which in turn is a copy of the information in the DNA molecule. Changes in the primary structure can alter the proper functioning of the protein. Protein function is usually tied to their three-dimensional structure. The primary structure is the sequence of amino acids in a polypeptide.

Structure of a protein: primary, secondary, tertiary, and quaternary levels of structure.

The secondary structure is the tendency of the polypeptide to coil or pleat due to H-bonding between R-groups. The tertiary structure is controlled by bonding (or in some cases repulsion) between R-groups. Many proteins, such as hemoglobin, are formed from one or more polypeptides. Such structure is termed quaternary structure. Structural proteins, such as collagen, have regular repeated primary structures. Like the structural carbohydrates, the components determine the final shape and ultimately function. Collagens have a variety of functions in living things, such as the tendons, hide, and corneas of a cow. Keratin is another structural protein. It is found in fingernails, feathers, hair, and rhinoceros horns. Microtubules, important in cell division and structures of flagella and cilia (among other things), are composed of globular structural proteins.

4. Nucleic acids are polymers composed of monomer units known as nucleotides. There are a very few different types of nucleotides. The main functions of nucleotides are information storage (DNA), protein synthesis (RNA), and energy transfers (ATP and NAD). Nucleotides consist of a sugar, a nitrogenous base, and a phosphate. The sugars are either ribose or deoxyribose. They differ by the lack of one oxygen in deoxyribose. Both are pentoses usually in a ring form. There are five nitrogenous bases. Purines (Adenine and Guanine) are double-ring structures, while pyrimidines (Cytosine, Thymine and Uracil) are single-ringed.

Structure of two types of nucleotide.

Deoxyribonucleic acid (better known as DNA) is the physical carrier of inheritance for 99% of living organisms. The bases in DNA are C, G, A and T. We will learn more about the DNA structure and function later in the course (click here for a quick look [actually take all the time you want!] ;)). DNA functions in information storage. The English alphabet has 26 letters and over 50,000 words. DNA has 4 letters (C, G, A, and T) and 20 words (the 20 amino acids) that can make an infinite variety of sentences (polypeptides).

Structure of a segment of a DNA double helix.

Changes in information can alter the meaning of a sentence.

For example take the sentence: I saw Elvis. This implies certain knowledge (that I've been out in the sun too long without a hat, etc.).

If we alter the sentence by inverting the middle word, we get: I was Elvis (thank you, thank you very much). Now we have greatly altered the information.

A third alteration will change the meaning: I was Levis. Clearly the original sentence's meaning is now greatly changed.

Changes in DNA information will be translated into changes in the primary structure of a polypeptide, and from there to the secondary and tertiary structures. A mutation is any change in the DNA base sequence. Most mutations are harmful, few are neutral, and a very few are beneficial and contribute the organism's reproductive success. Mutations are the wellspring of variation, variation is central to Darwin and Wallace's theory of evolution by natural selection.

Ribonucleic acid (RNA) was discovered after DNA. DNA, with exceptions in chloroplasts and mitochondria, is restricted to the nucleus (in eukaryotes, the nucleoid region in prokaryotes). RNA occurs in the nucleus as well as in the cytoplasm (also remember that it occurs as part of the ribosomes that line the rough endoplasmic reticulum). There are three types of RNA:

Messenger RNA (mRNA) is the blueprint for construction of a protein.

Ribosomal RNA (rRNA) is the construction site where the protein is made.

Transfer RNA (tRNA) is the truck delivering the proper amino acid to the site at the right time.

Details of RNA and its role in protein synthesis are available by clicking here.

Structure a RNA molecule.

Learning Objectives Dissolved substances are called solutes; a fluid in which one or more substances

can dissolve is called a solvent. Describe several solutions that you use everyday in terms of what is the solvent and what is the solute.

Define acid and base and be able to cite an example of each. The concentration of free hydrogen ions in solutions is measured by the pH scale.. Nearly all large biological molecules have theor organization influenced by

interactions with water. Describe this interaction as it exists with carbohydrate molecules.

Be able to list the three most abundant elements in living things. Each carbon atom can form as many as four covalent bonds with other carbon

atoms as well as with other elements. Be able to explain why this is so. Be able to list the four main groups of organic molecules and their functions in

living things. Enzymes are a special class of proteins that speed up chemical reactions in cells.

What about the structure of proteins allows for the reaction specificity that occurs with most enzymes.

Condensation reactions result in the formation of covalent bonds between small molecules to form larger organic molecules. Be able to describe a condensation reaction in words.

Be able to describe what occurs during a hydrolysis reaction. Be able to define carbohydrates and list their functions.

The simplest carbohydrates are sugar monomers, the monosaccharides. Be able to give examples and their functions.

A polysaccharide is a straight or branched chain of hundreds or thousands of sugar monomers, of the same or different kinds. Be able to give common examples and their functions.

Be able to define lipids and to list their functions. Distinguish betwen a saturated fat and an unsaturated fat. Why is such a

distinction a life and death matter for many people? A phospholipid has two fatty acid tails attached to a glycerol backbone. What is

the importance of these molecules. Define steroids and describe their chemical structure. Be able to discuss the

importance of the steroids known as cholesterol and hormones. Be able to describe proteins and cite their general functions. Be prepared to make a sketch and name the three parts of every amino acid.

o Describe the complex structure of a protein through its primary, secondary, tertiary, and quaternary structure. How does this relate to the three-dimensional structure of proteins?

Describe the three parts of every nucleotide..

Chemistry Dictionary Absolute Entropy (of a substance)

The increase in the entropy of a substance as it goes from a perfectly ordered crystalline form at 0 K (where its entropy is zero) to the temperature in question.

Absolute Zero The zero point on the absolute temperature scale; -273.15C or 0 K; theoretically, the temperature at which molecular motion ceases.

Absorption Spectrum Spectrum associated with absorption of electromagnetic radiation by atoms (or other species) resulting from transitions from lower to higher energy states.

Accuracy How closely a measured value agrees with the correct value.

Acid A substance that produces H+(aq) ions in aqueous solution. Strong acids ionize completely or almost completely in dilute aqueous solution. Weak acids ionize only slightly.

Acid Anhydride The oxide of a nonmetal that reacts with water to form an acid.

Acid Anhydride Compound produced by dehydration of a carbonic acid; general formula is R--C--O--C--R

Acidic Salt A salt containing an ionizable hydrogen atom; does not necessarily produce acidic solutions.

Activation Energy Amount of energy that must be absorbed by reactants in their ground states to reach the transition state so that a reaction can occur.

Active Metal Metal with low ionization energy that loses electrons readily to form cations.

Activity (of a component of ideal mixture) A dimensionless quantity whose magnitude is: equal to molar concentration in an ideal solution; equal to partial pressure in an ideal gas mixture; and defined as 1 for pure solids or liquids.

Activity Series A listing of metals (and hydrogen) in order of decreasing activity

Actual Yield Amount of a specified pure product actually obtained from a given reaction. Compare with Theoretical Yield.

Actinides Elements 90 to 103 (after actinium)

Acyl Group Compound derived from a carbonic acid by replacing the --OH group with a halogen (X), usually --Cl; general formula is O R--C--X

Addition Reaction

A reaction in which two atoms or groups of atoms are added to a molecule, one on each side of a double or triple bond

Adhesive Forces Forces of attraction between a liquid and another surface.

Adsorption Adhesion of a species onto the surfaces of particles

Alcohol Hydrocarbon derivative containing an --OH group attached to a carbon atom not in an aromatic ring.

Aldehyde Compound in which an alkyl or aryl group and a hydrogen atom are attached to a carbonyl group and a hydrogen atom are attached to a carbonyl group; general formula, O-R-C-H

Alkali Metals Metals of Group IA (Na, K, Rb).

Alkaline Battery A dry cell in which the electrolyte contains KOH.

Alkaline Earth Metals Group IIA metals

Alkenes (Olefins) Unsaturated hydrocarbons that contain one or more carbon-carbon double bonds.

Alkyl Group A group of atoms derived from an alkane by the removal of one hydrogen atom.

Alkylbenzene A compound containing an alkyl group bonded to a benzene ring.

Alkynes Unsaturated hydrocarbons that contain one or more carbon-carbon triple bonds.

Allotropes Different forms of the same element in the same physical state.

Allotropic Modifications (Allotropes) Different forms of the same element in the same physical state.

Alloying Mixing of metal with other substances (usually other metals) to modify its properties.

Alpha Particle A helium nucleus.

Alpha (a) Particle Helium ion with 2+ charge; an assembly of two protons and two neutrons.

Alums Hydrated sulfates of the general formula M+M3+(SO4)2.12H2).

Amide Compound containing the O-C-N group. Compound that can be considered a derivative of ammonia in which one or more hydrogens are replaced by a alkyl or aryl groups.

Amine

Derivatives of ammonia in which one or more hydrogen atoms have been replaced by organic groups.

Amine Complexes Complex species that contain ammonia molecules bonded to metal ions.

Amino Acid Compound containing both an amino and a carboxylic acid group.The --NH2 group. :Amino Acids

Amorphous Solid A noncrystalline solid with no well-defined ordered structure.

Ampere Unit of electrical current; one ampere equals one coulomb per second.

Amphiprotism Ability of a substance to exhibit amphiprotism by accepting donated protons.

Amphoterism The ability to react with both acids and bases. Ability of substance to act as either an acid or a base.

Anion A negative ion; an atom or goup of atoms that has gained one or more electrons.

Anode In a cathode ray tube, the positive electrode. Electrode at which oxidation occurs.

Antibonding Orbital A molecular orbital higher in energy than any of the atomic orbitals from which it is derived; lends instability to a molecule or ion when populated with electrons; denoted with a star (*) superscript or symbol.

Aromatic Hydrocarbons Benzene and its derivatives.

Artificial Transmutation An artificially induced nuclear reaction caused by the bombardment of a nucleus with subatomic particiles or small nucei.

Aryl Group Group of atoms remaining after a hydrogen atom is removed from the aromatic system.

Associated Ions Short-lived species formed by the collision of dissolved ions of opposite charges.

Atmosphere A unit of pressure; the pressure that will support a column of mercury 760 mm high at 0 C.

Atom The smallest particle of an element

Atomic Mass Unit (amu) One twelfth of a mass of an atom of the carbon-12 isotope; a unit used for stating atomic and formula weights; also called dalton.

Atomic Number Integral number of protons in the nucleus; defines the identity of element.

Atomic Orbital Region or volume in space in which the probability of finding electrons is highest.

Atomic Radius Radius of an atom.

Atomic Weight Weighted average of the masses of the constituent isotopes of an element; The relative masses of atoms of different elements.

Aufbau ('building up') Principle Describes the order in which electrons fill orbitals in atoms.

Autoionization An ionization reaction between identical molecules.

Avogadro's Law At the same temperature and pressure, equal volumes of all gases contain the same number of molecules.

Avogadro's Number The number (6.022x10^23) of atoms, molecules or particles found in exactly 1 mole of substance.

Background Radiation Ratiation extraneous to an experiment. Usually the low-level natural radiation form cosmic rays and trace radioactive substances present in our environment.

Band A series of very closely spaced, nearly continuous molecular orbitals that belong to the crystal as a whole.

Band of Stability Band containing nonradioactive nuclides in a plot of number of neutrons versus atomic number.

Band Theory of Metals Theory that accounts for the bonding and properties of metallic solids.

Barometer A device for measuring pressure.

Base A substance that produces OH (aq) ions in aqueous solution. Strong soluable bases are soluble in water and are completely dissociated. Weak bases ionize only slightly.

Basic Anhydride The oxide of a metal that reacts with water to form a base.

Basic Salt A salt containing an ionizable OH group.

Beta Particle Electron emitted from the nucleus when a neuton decays to a proton and an electron.

Biodegradability The ability of a substance to be broken down into simpler substances by bacteria.

Binary Acid A binary compound in which H is bonded to one or more of the more electronegative nonmetals.

Binary Compound A compound consisting of two elements; may be ionic or covalent.

Binding Energy (nuclear binding energy) The energy equivalent (E = mc^2) of the mass deficiency of an atom. where: E = is the energy in joules, m is the mass in kilograms, and c is the speed of light in m/s^2

Boiling Point The temperature at which the vapor pressure of a liquid is equal to the applied pressure; also the condensation point

Boiling Point Elevation The increase in the boiling point of a solvent caused by the dissolution of a nonvolatile solute.

Bomb Calorimeter A device used to measure the heat transfer between system and surroundings at constant volume. Analytical Chemistry

Bond Energy The amount of energy necessary to break one mole of bonds of a given kind (in gas phase). The amount of energy necessary to break one mole of bonds in a substance, dissociating the sustance in the gaseous state into atoms of its elements in the gaseous state.

Bond Order Half the numbers of electrons in bonding orbitals minus half the number of electrons in antibonding orbitals.

Bonding Orbital A molecular orbit lower in energy than any of the atomic orbitals from which it is derived; lends stability to a molecule or ion when populated with electron

Bonding Pair Pair of electrons involved in a covalent bond.

Boron Hydrides Binary compounds of boron and hydrogen.

Born-Haber Cycle A series of reactions (and accompanying enthalpy changes) which, when summed, represents the hypothetical one-step reaction by which elements in their standard states are converted into crystals of ionic compounds (and the accompanying enthalpy changes.)

Boyle's Law At constant temperature the volume occupied by a definite mass of a gas is inversely proportional to the applied pressure.

Breeder Reactor A nuclear reactor that produces more fissionable nuclear fuel than it consumes.

Bronsted-Lowry Acid A proton donor.

Bronsted-Lowry Base A proton acceptor

Buffer Solution Solution that resists change in pH; contains either a weak acid and a soluble ionic salt of the acid or a weak base and a soluble ionic salt of the base.

Buret A piece of volumetric glassware, usually graduated in 0.1-mL intervals, that is used to deliver solutions to be used in titrations in a quantitative (dropwise) manner.

Calorie The amount of heat required to raise the temperature of one gram of water from 14.5C to 15.5C. 1 calorie = 4.184 joules.

Calorimeter A device used to measure the heat transfer between system and surroundings. Analytical Chemistry

Canal Ray Stream of positively charged particles (cations) that moves toward the negative electrode in cathode ray tubes; observed to pass through canals in the negative electrode.

Capillary A tube having a very small inside diameter.

Capillary Action The drawing of a liquid up the inside of a small-bore tube when adhesive forces exceed cohesive forces, or the depression of the surface of the liquid when cohesive forces exceed the adhesive forces.

Carbanion An organic ion carrying a negative charge on a carbon atom.

Carbonium ion An orgainic ion carrying a positive charge on a carbon atom.

Carcinogen A substance capable of causing or producing cancer in mammals.

Catalyst A substance that speeds up a chemical reaction without being consumed itself in the reaction. A substance that alters (usually increases) the rate at which a reaction occurs.

Catenation Bonding of atoms of the same element into chains or rings. The bonding together of atoms of the same element to form chains. The ability of an element to bond to itself.

Cathode Electrode at which reduction occurs In a cathode ray tube, the negative electrode.

Cathodic Protection Protection of a metal (making ir a cathode) against corrosion by attaching it to a sacrifical anode of a more easily oxidized metal.

Cathode Ray Tube

Closed glass tube containing a gas under low pressure, with electrodes near the ends and a luminescent screen at the end near the positive electrode; produces cathode rays when high voltage is applied.

Cation A positive ion; an atom or group of atoms that has lost one or more electrons.

Cell Potential Potential difference, Ecell, between oxidation and reduction half-cells under nonstandard conditions.

Central Atom An atom in a molecule or polyatomic ion that is bonded to more than one other atom.

Chain Reaction A reaction that, once initiated, sustains itself and expands. This is a reaction in which reactive species, such as radicals, are produced in more than one step. These reactive species, radicals, propagate the chain reaction.

Chain Termination Step The combination of two radicals, which removes the reactive species that propagate the change reaction.

Charle's Law At constant pressure the volume occupied by a definite mass of gas is directly proportional to its absolute temperature.

Chemical Bonds The attractive forces that hold atoms together in elements or compounds.

Chemical Change A change in which one or more new substances are formed.

Chemical Equation Description of a chemical reaction by placing the formulas of the reactants on the left and the formulas of products on the right of an arrow.

Chemical Equilibrium A state of dynamic balance in which the rates of forward and reverse reactions are equal; there is no net change in concentrations of reactants or products while a system is at equilibrium.

Chemical Hygiene Officer (CHO) A person or employee who is qualified by training or experience to provide technical guidance in the development and implementations of the provisions of a Chemical Hygiene Plan (CHP)

Chemical Hygiene Plan (CHP) A written program developed and implemented by an employer designating proceedures, equipment, personal protective equipment, and work practices that are capable of protecting employees from the health hazards presented by hazardous chemicals usid in that particular workplace.

Chemical Kinetics The study of rates and mechanisms of chemical reactions and of the factors on which they depend.

Chemical Periodicity The variations in properties of elements with their position in the periodic table

Cis- The prefix used to indicate that groups are located on the same side of a bon about which rotation is restricted.

Cis-Trans Isomerism A type of geometrical isomerism related to the angles between like ligands.

Clay A class of silicate and aluminosilicate minerals with sheet-like structures that have enormous surface areas that can absorb large amounts of water.

Cloud Chamber A device for observing the paths of speeding particiles as vapor molecules condense on them to form foglike tracks.

Coefficient of expansion The ratio of the change in length or volumen of a body to the original lengthor volume for a unit change in temperature.

Cohesive Forces All the forces of attraction among particles of a liquid.

Coke An impure form of carbon obtained by destructive distillation of coal or petroleum.

Colligative Properties Physical properties of solutions that depend upon the number but not the kind of solute particles present.

Collision Theory Theory of reaction rates that states that effective collisions between reactant molecules must occur in order for the reaction to occur.

Colloid A heterogeneous mixture in which solute-like particles do not settle out.

Combination Reaction Reaction in which two substances ( elements or compounds ) combine to form one compound. Reaction of a substance with oxygen in a highly exothermic reaction, usually with a visible flame.

Combustible Classification of liquid substances that will burn on the basis of flash points. A combustible liquid means any liquid having a flash point at or above 37.8C (100F) but below 93.3C (200F), except any mixture having components with flash points of 93.3C (200F) or higher, the total of which makes up 99 percent or more of the total volume of the mixture.

Common Ion Effect Suppression of ionization of a weak electrolyte by the presence in the same solution of a strong electrolyte containing one of the same ions as the weak electrolyte.

Complex Ions Ions resulting from the formation of coordinate covalent bonds between simple ions and other ions or molecules.

Composition Stoichiometry

Descibes the quantitative (mass) relationships among elements in compounds. Compound

A substance of two or more elements in fixed proportions. Compounds can be decomposed into their constituent elements. Compounds

Compressed Gas A gas or mixture of gases having, in a container an absolute pressure exceeding 40 psi at 21.1C (70F) A gass or mixture having in a container, an absolute pressure exceeding 104 psi at 54.4C (130F) regardless of the pressure at (21.1C (70F) A liquid having a vapour pressure exceeding 40 psi at 37.8C (70F) as determined by ASTM D-323-72.

Concentration Amount of solute per unit volume or mass of solvent or of solution.

Condensation Liquefaction of vapor.

Condensed Phases The liquid and solid phases; phases in which particles interact strongly.

Condensed States The solid and liquid states.

Conduction Band A partially filled band or a band of vacant energy levels just higher in energy than a filled band; a band within which, or into which, electrons must be promoted to allow electrical conduction to occur in a solid.

Conjugate Acid-base Pair In Bronsted-Lowry terminology, a reactant and product that differ by a proton, H+.

Conformations Structures of a compound that differ by the extent of rotation about a single bond.

Continuous Spectrum Spectrum that contains all wave-lengths in a specified region of the electromagnetic spectrum.

Control Rods Rods of materials such as cadmium or boron steel that act as neutron obsorbers (not merely moderaters) used in nuclear reactors to control neutron fluxes and therfore rates of fission.

Conjugated Double Bonds Double bonds that are separated from each other by one single bond -C=C-C=C-.

Contact Process Industrial process by which sulfur trioxide and sulfuric acid are produced from sulfur dioxide.

Coordinate Covalent Bond Covalent bond in which both shared electrons are furnished by the same species; bond between a Lewis acid and Lewis base.

Coordinate Covalent Bond

A covalent bond in which both shared electrons are donated by the same atom; a bond between a Lewis base and a Lewis acid.

Coordination Compound or Complex A compound containing coordinate covalent bonds.

Coordination Isomers Isomers involving exchanges of ligands between complex cation and complex anion of the same compound.

Coordination Number In describing crystals, the number of nearest neighbours of an atom or ion. The number of donor atoms coordinated to a metal.

Coordination Sphere The metal ion and its coordinating ligands but not any uncoordinated counter-ions.

Corrosion Oxidation of metals in the presence of air and moisture. Corrosion

Coulomb Unit of electrical charge.

Coulometry The quantitative application of Faraday's Law to the analysis of materials. The current and time are the usual variables measured.

Covalent Bond Chemical bond formed by the sharing of one or more electron pairs between two atoms.

Covalent Compounds Compounds containing predominantly covalent bonds.

Critical Mass The minimum mass of a particular fissionable nuclide in a given volume required to sustain a nuclear chain reaction.

Critical Point The combination of critical temperature and critical pressure of a substance.

Critical Pressure The pressure required to liquefy a gas (vapor) at its critical temperature.

Critical Temperature The temperature above which a gas cannot be liquefied; the temperature above which a substance cannot exhibit distinct gas and liquid phases.

Crystal Field Stabilization Energy A measure of the net energy of stabilization gained by a metal ion's nonbonding d electrons as a result of complex formation. Crystallography

Crystal Field Theory Theory of bonding in transition metal complexes in which ligands and metal ions are treated as point charges; a purely ionic model; ligand point charges represent the crystal (electrical) field perturbing the metal?s d orbitals containing nonbonding electrons.

Crystal Lattice

A pattern of arrangement of particles in a crystal. Crystallography

Crystal Lattice Energy Amount of energy that holds a crystal together; the energy change when a mole of solid is formed from its constituent molecules or ions (for ionic compounds) in their gaseous state. The energy charge when one mole of formula units of a crystalline solid is formed from its ions, atoms, or molecules in the gas phase; always negative. Crystallography

Crystalline Solid A solid characterized by a regular, ordered arrangement of particles. Crystallography

Curie (Ci) The basic unit used to describe the intensity of radioactivity in a sample of material. One curie equals 37 billion disintegrations per second or approximately the amount of radioactivty given off by 1 gram of radium.

Cyclotron A device for accelerating charged particles along a spiral path.

Daughter Nuclide Nuclide that is produced in a nuclear decay.

Debye The unit used to express dipole moments.

Degenerate Of the same energy.

Delocalization Of electrons; refers to bonding electrons that are distributed among more than two atoms that are bonded together; occurs in species that exhibit resonance. The formation of a set of molecular orbitals that extend over more than two atoms; important in species that valence bond theory describes in terms of resonance.

Denaturation A process pertaining to a change in structure of a protein form regular to irregular arrangement of the polypeptide chains.

Denatured A commercial term used to describe ethanol that has been rendered unfit for human consumption because of the addition of harmful ingredients to make it sales tax-expempt.

Density Mass per unit Volume: D=MV

Deposition The direct solidification of a vapor by cooling; the reverse of sublimation.

Derivative A compound that can be imagined to arise from a partent compound by replacement of one atom with another atom or group of atoms. Used extensively in orgainic chemistry to assist in identifying compounds.

Dermal toxicity

Adverse health effects resulting from skin exposure ot a substance. Designated area

An area that may be used for work with carcinogens, reproductive toxins, or substances that have a high degree of acute toxicity. A designated area may be the entire laboratory, an area of a laboratory, or a device such as a loboratory hood.

Detergent A soap-like emulsifer that contains a sulfate, SO3 or a phosphate group instead of a carboxylate group.

Deuterium An isotope of hydrogen whose atoms are twice as massive as ordinary hydrogen;deuterion atoms contain both a proton and a neutron in the nucleus.

Dextrorotatory Refers to an optically active substance that rotates the plane of plane polarized light clockwise; also called dextro.

Diagonal Similarities Refers to chemical similarities in the Periodic Table of elements of Period 2 to elements of Period 3 one group to the right; especially evident toward the left of the periodic table.

Diamagnetism Weak repulsion by a magnetic field.

Differential Scanning Calorimetry (DSC) A technique for measuring the temperature, direction, and magnitude of thermal transitions in a sample material by heating/cooling and comparing the amount of energy required to maintain its rate of temperature increase or decrease with an inert reference material under similar conditions.

Differential Thermal Analysis (DTA) A technique for observing the temperature, direction, and magnitude of thermally induced transitions in a material by heating/cooling a sample and comparing its temperature with that of an inert reference material under similar conditions.

Differential Thermometer A thermometer used for accurate measurement of very small changes in temperature.

Dilution Process of reducing the concentration of a solute in solution, usually simply by mixing with more solvent.

Dimer Molecule formed by combination of two smaller (identical) molecules.

Dipole Refers to the separation of charge between two covalently bonded atoms

Dipole-dipole Interactions Attractive interactions between polar molecules, that is, between molecules with permanent dipoles.

Dipole Moment The product of the distance separating opposite charges of equal magnitude of the charge; a measure of the polarity of a bond or molecule; a measured dipole moment refers to the dipole moment of an entire molecule.

Dispersing Medium The solvent-like phase in a colloid.

Dispersed Phase The solute-like species in a colloid.

Displacement Reactions Reactions in which one element displaces another from a compound.

Disproportionation Reactions Redox reactions in which the oxidizing agent and the reducing agent are the same species.

Dissociation In aqueous solution, the process in which a solid ionic compound separates into its ions.

Dissociation Constant Equilibrium constant that applies to the dissociation of a comples ion into a simple ion and coordinating species (ligands).

Distilland The material in a distillation apparatus that is to be distilled.

Distillate The material in a distillation apparatus that is collected in the receiver.

Distillation The separation of a liquid mixture into its components on the basis of differences in boiling points. The process in which components of a mixture are separated by boiling away the more volitile liquid.

Domain A cluster of atoms in a ferromagnetic substance, all of which align in the same direction in the presence of an external magnetic field.

Donor Atom A ligand atom whose electrons are shared with a Lewis acid.

D-Orbitals Beginning in the third energy level, aset of five degenerate orbitals per energy level, higher in energy than s and p orbitals of the same energy level.

Dosimeter A small, calibrated electroscope worn by laboratory personnel and designated to detect and measure incident ionizing radiation or chemical exposure.

Double Bond Covalent bond resulting from the sharing of four electrons (two pairs) between two atoms.

Double Salt Solid consisting of two co-crystallized salts.

Doublet Two peaks or bands of about equal intensity appearing close together on a spectrogram.

Downs Cell Electrolytic cell for the commercial electrolysis of molten sodium chloride.

DP number

The degree of polymerization; the average number of monomer units per polymer unit.

Dry Cells Ordinary batteries (voltaic cells) for flashlights. radios, and so on; many are Leclanche cells.

D -Transition elements (metals) B Group elements except IIB in the periodic table; sometimes called simply transition elements EX. Fe, Ni, Cu, Ti .

Dumas Method A method used to determine the molecular weights of volatile liquids.

Dynamic Equilibrium An equilibrium in which processes occur continuously, with no net change. When two (or more) processes occur at the same rate so that no net change occurs.

Effective Collisons Collision between molecules resulting in a reaction; one in which the molecules collide with proper relative orientations and sufficient energy to react.

Effective Molality The sum of the molalities of all solute particles in a solution.

Effective Nuclear Charge The nuclear charge experienced by the outermost electrons of an atom; the actual nuclear charge minus the effects of shielding due to inner-shell electrons. Example: Set of dx2-y2 and dz2 orbitals; those d orbitals within a set with lobes directed along the x-, y-, and z-axes.

Electrical Conductivity Ability to conduct electricity.

Electrochemistry Study of chemical changes produced by electrical current and the production of electricity by chemical reactions.

Electrodes Surfaces upon which oxidation and reduction half-reactions; occur in electrochemical cells.

Electrode Potentials Potentials, E, of half-reactions as reductions versus the standard hydrogen electrode.

Electrolysis Process that occurs in electrolytic cells.

Electrolyte A substance whose aqueous solutions conduct electricity.

Electrolytic Cells Electrochemical cells in which electrical energy causes nospontaneous redox reactions to occur. An electrochemical cell in which chemical reactions are forced to occur by the application of an outside source of electrical energy.

Electrolytic Conduction

Conduction of electrical current by ions through a solution or pure liquid. Electromagnetic Radiation

Energy that is propagated by means of electric and magnetic fields that oscillate in directions perpendicular to the direction of travel of the energy.

Electromotive Series The relative order of tendencies for elements and their simple ions to act as oxidizing or reducing agents; also called the activity series.

Electron A subatomic particle having a mass of 0.00054858 amu and a charge of 1-.

Electron Affinity The amount of energy absorbed in the process in which an electron is added to a neutral isolated gaseous atom to form a gaseous ion with a 1- charge; has a negative value if energy is released.

Electron Configuration Specific distribution of electrons in atomic orbitals of atoms or ions.

Electron Deficient Compounds Compounds that contain at least one atom (other than H) that shares fewer than eight electrons

Electronic Transition The transfer of an electron from one energy level to another.

Electronegativity A measure of the relative tendency of an atom to attract electrons to itself when chemically combined with another atom.

Electronic Geometry The geometric arrangement of orbitals containing the shared and unshared electron pairs surrounding the central atom of a molecule or polyatomic ion.

Electrophile Positively charged or electron-deficient.

Electrophoresis A technique for separation of ions by rate and direction of migration in an electric field.

Electroplating Plating a metal onto a (cathodic) surface by electrolysis.

Element A substance that cannot be decomposed into simpler substances by chemical means.

Eluant or eluent The solvent used in the process of elution, as in liquid chromatography.

Eluate Solvent (or mobile phase) which passes through a chromatographic column and removes the sample components from the stationary phase.

Emission Spectrum Spectrum associated with emission of electromagnetic radiation by atoms (or other species) resulting from electronic transitions from higher to lower energy states.

Emulsifying Agent

A sustance that coats the particles of the dispersed phase and prevents coagulation of colloidal particles; an emulsifier.

Emulsion Colloidal suspension of a liquid in a liquid.

Enantiomer One of the two mirror-image forms of an optically active molecule.

Endothermic Describes processes that absorb heat energy.

Endothermicity The absorption of heat by a system as the process occurs.

End Point The point at which an indicator changes colour and a titration is stopped.

Energy The capacity to do work or transfer heat.

Enthalpy The heat content of a specific amount of substance; defined as E= PV.

Entropy A thermodynamic state or property that measures the degree of disorder or randomness of a system.

Enzyme A protein that acts as a catalyst in biological systems.

Equation of State An equation that describes the behavior of matter in a g

Green B. Fundamentals of Chemistry 2007

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