Chapter 2 Atoms and Elements. Dalton’s Atomic Theory ( beginning of 19 th century ) All matter is...
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Transcript of Chapter 2 Atoms and Elements. Dalton’s Atomic Theory ( beginning of 19 th century ) All matter is...
Chapter 2Chapter 2
Atoms and ElementsAtoms and Elements
Dalton’s Atomic TheoryDalton’s Atomic Theory((beginning of 19beginning of 19thth century century))
• All matter is composed of tiny, All matter is composed of tiny, indivisible indivisible particles called atoms particles called atoms
• All atoms of a given element are All atoms of a given element are identical to each other and different identical to each other and different from those of other elementsfrom those of other elements
• A chemical reaction merely involves A chemical reaction merely involves a change in the groupings of atoms a change in the groupings of atoms and not creation or destruction of and not creation or destruction of atoms (Law of Conservation of Mass)atoms (Law of Conservation of Mass)
• Compounds consist of atoms of Compounds consist of atoms of more than one element combined in more than one element combined in particular ratios (Law of Constant particular ratios (Law of Constant Composition and Law of Multiple Composition and Law of Multiple Proportions)Proportions)
Building up Atomic StructureBuilding up Atomic Structure• Benjamin Franklin (1706-1790) discovered two Benjamin Franklin (1706-1790) discovered two
types of electricity, (+) and (-). types of electricity, (+) and (-). • Henri Becquerel discovered radioactivity on 1896. Henri Becquerel discovered radioactivity on 1896.
Pierre and Marie Curie continued that work: Pierre and Marie Curie continued that work: atoms disintegrate, i.e., they are atoms disintegrate, i.e., they are divisibledivisible..
• John J. Thomson discovered the John J. Thomson discovered the electronelectron and and determined its charge/mass ratio (1896-97).determined its charge/mass ratio (1896-97).
• Robert A. Millikan (1909) determined the charge Robert A. Millikan (1909) determined the charge and mass of electron.and mass of electron.
• Ernest Rutherford (1911-19) discovered the Ernest Rutherford (1911-19) discovered the protonproton..
• James Chadwick (1932) discovered the James Chadwick (1932) discovered the neutronsneutrons, , that are with the protons in the that are with the protons in the nucleusnucleus of atoms. of atoms.
Atomic StructureAtomic Structure
• subatomic particlessubatomic particles neutronneutron: no charge, 1.0087 amu, n: no charge, 1.0087 amu, n protonproton: +1 charge, 1.0073 amu, p: +1 charge, 1.0073 amu, p++
electronelectron: –1 charge, 0.0005486 amu, e: –1 charge, 0.0005486 amu, e––
• n and pn and p++ packed tightly into dense core packed tightly into dense core called called nucleusnucleus
• ee–– distributed more diffusely in space distributed more diffusely in space surrounding nucleussurrounding nucleus
e–
np+
e–Actual size: Radius of atom ~ 100 pm (10-10 m)Radius of nucleus ~ 0.001 pmThen, if radius of atom was ~ 100 m (a small football stadium), the radius of the nucleus would be ~ 0.001 m = 1 mm V r3 Then, Vatom/Vnucleus 1015. Atom is 1015 times bigger
• all atoms of a given element have the all atoms of a given element have the same number of protonssame number of protons
• number of protonsnumber of protons in an atom given by in an atom given by the the atomic numberatomic number, Z, Z
• neutral atoms have same number of neutral atoms have same number of protons and electronsprotons and electrons
• atoms gain or lose charge by gaining or atoms gain or lose charge by gaining or losing electrons only (not protons)losing electrons only (not protons)
• total number of protons and neutrons total number of protons and neutrons given by given by mass number, A. A = #pmass number, A. A = #p++ + #n + #n
Atomic number and Mass number
SymbolSymbol
XXZZ
AA nn
atomic numberatomic number
chargecharge
element symbolelement symbol
mass numbermass number
ExamplesExamples
Determine the numbers of electrons, Determine the numbers of electrons, protons, and neutrons in each of the protons, and neutrons in each of the following atoms.following atoms.
ArAr4040
1818
Z = 18, therefore the atom has 18 pZ = 18, therefore the atom has 18 p++
A = 40, A = 40,
A = # of pA = # of p++ + # of neutrons + # of neutrons
Therefore, # neutrons = A Therefore, # neutrons = A − # p− # p++
40 – 18 = 22 neutrons40 – 18 = 22 neutrons
Charge, n = 0, therefore # of eCharge, n = 0, therefore # of e–– = # p = # p++ = 18 = 18
ArAr4040
1818
PbPb209209
8282
2+2+
• Z = 82, therefore 82 pZ = 82, therefore 82 p++
• A = 209, therefore 209 pA = 209, therefore 209 p+ + and n totaland n total
• # neutrons = A # neutrons = A − # p− # p++ = 209 – 82 = 127 n = 209 – 82 = 127 n
• n = 2+, n = 2+,
• Therefore # eTherefore # e–– = 82 p = 82 p++ − 2 =− 2 = 80 e 80 e–– ( (lost 2 elost 2 e––))
PP3131
15153–3–
Z = 15, therefore 15 pZ = 15, therefore 15 p++
PP3131
15153–3–
Z = 15, therefore 15 pZ = 15, therefore 15 p++
A = 31, therefore 31 pA = 31, therefore 31 p++ and n total and n total
PP31311515
3–3–
Z = 15, therefore 15 pZ = 15, therefore 15 p++
A = 31, therefore 31 pA = 31, therefore 31 p++ and n total and n total
31 – 15 = 16 n31 – 15 = 16 n
PP3131
1515
3–3–
Z = 15, therefore 15 pZ = 15, therefore 15 p++
A = 31, therefore 31 pA = 31, therefore 31 p++ and n total and n total
31 – 15 = 16 n31 – 15 = 16 n
n = 3 –, (gained 3 en = 3 –, (gained 3 e––))
Therefore, # eTherefore, # e−− = 15 + 3 = 18 e = 15 + 3 = 18 e−−
PP3131
15153–3–
IsotopesIsotopes
• atoms (of same element) that have atoms (of same element) that have the same number of protons but the same number of protons but different numbers of neutrons, i.e., different numbers of neutrons, i.e., different different AA
• may or may not have same number may or may not have same number of electronsof electrons
XX52522424 XX
55552424
XX52522424 XX
55552424
XX52522424 XX
52522020
XX5252
2424XX
5555
2424
XX5252
2424 XX5252
2020
XX5252
2424XX
5050
2424
3+3+
Which of the Which of the pairs of atoms pairs of atoms
is(are) is(are) isotope(s)?isotope(s)?
Isotope abundanceIsotope abundanceA sample of naturallyA sample of naturallyoccurring sulfur containsoccurring sulfur containsseveral isotopes with theseveral isotopes with thefollowing abundancesfollowing abundances
Isotope % abundanceIsotope % abundance 3232S S 95.02 95.02 3333SS 0.75 0.75 3434S S 4.21 4.21 3636SS 0.02 0.02
The %s have been determined experimentally.The %s have been determined experimentally.
# of atoms of a given isotope# of atoms of a given isotope% Abundance = % Abundance = ──────────────────────────────────────────────────────── x 100 x 100 Total # of atoms of all isotopes of element Total # of atoms of all isotopes of element
32S, 33S, 34S, 36S16 16 16 16
Mass Spectrometry is employed to Mass Spectrometry is employed to determine Isotopic Abundancesdetermine Isotopic Abundances
• mass spectrometer.mass spectrometer.– Device generates ions that pass down an Device generates ions that pass down an
evacuated path inside a magnet.evacuated path inside a magnet.– Ions are separated based on their Ions are separated based on their
charge/mass ratio. Mass is, then, calculated.charge/mass ratio. Mass is, then, calculated.
Atomic WeightAtomic Weight
The atomic mass and Isotope Abundances areThe atomic mass and Isotope Abundances aredetermined by means of determined by means of Mass SpectrometryMass Spectrometry..
Atomic mass of isotope Atomic mass of isotope carbon-12 is defined exactly 12 carbon-12 is defined exactly 12 amuamu whereas all others of carbon and other elements whereas all others of carbon and other elementsare referred to that and do not have integer values.are referred to that and do not have integer values.
% abundance isotope 1Atomic weightAtomic weight = = x (mass isotope 1) x (mass isotope 1) 100100
% abundance isotope 2 % abundance isotope 2 + + x (mass isotope 2) + … x (mass isotope 2) + … 100100
ExampleExample
Isotope % abundanceIsotope % abundance mass (amu)mass (amu)6464 Zn Zn 48.6 48.6 63.9291 63.92916666ZnZn 27.9 27.9 65.9260 65.92606767ZnZn 4.1 4.1 66.9721 66.97216868ZnZn 18.8 18.8 67.9249 67.92497070ZnZn 0.6 0.6 69.9253 69.9253
Example, contd.Example, contd.
%abund.%abund.ii
Atomic weight of Atomic weight of ZnZn = = ∑∑ m mii
100100
A.W.= 0.486 A.W.= 0.486 63.9291 + 0.279 63.9291 + 0.279 65.9260 + … 65.9260 + …
+ 0.041 + 0.041 66.9721 + 0.188 66.9721 + 0.188 67.9249 + … 67.9249 + …
+ 0.006 + 0.006 69.9253 = 69.9253 = 65.4 amu65.4 amu
# 25. Gallium has two naturally occurring isotopes, # 25. Gallium has two naturally occurring isotopes, 69Ga and 71Ga, with masses of 68.9257 amu and 69Ga and 71Ga, with masses of 68.9257 amu and 70.9249 amu, respectively. Calculate the % abundance 70.9249 amu, respectively. Calculate the % abundance of the two isotopes of Ga. of the two isotopes of Ga. A W Ga = 69.723 (Per. table)A W Ga = 69.723 (Per. table)
Let’s name p1 = % of 69Ga and p2 = % of 71Ga.Let’s name p1 = % of 69Ga and p2 = % of 71Ga.p1 + p2 = 100 then, p1 = 100 − p2 p1 + p2 = 100 then, p1 = 100 − p2 (1)(1)
p1 p1 68.9257 + p2 68.9257 + p2 70.9249 70.9249AW = 69.723 = ──────────────────── then,AW = 69.723 = ──────────────────── then, 1001006972.3 = p16972.3 = p168.9257 + p268.9257 + p270.9249 Then, replace p1 by 70.9249 Then, replace p1 by (1)(1) 6972.3 = (100 − p2) 6972.3 = (100 − p2) 68.9257 + p2 68.9257 + p2 70.9249 70.9249
6972.3 = 6892.57 − p2 6972.3 = 6892.57 − p2 68.9257 + p2 68.9257 + p2 70.9249 70.92496972.3 − 6892.57 = p2 6972.3 − 6892.57 = p2 (70.9249 − 68.9257) (70.9249 − 68.9257)
6972.3 − 6892.576972.3 − 6892.57p2 = ─────────── = 39.88% p1= 100 − p2 = 60.12% p2 = ─────────── = 39.88% p1= 100 − p2 = 60.12% 70.9249 − 68.925770.9249 − 68.9257
Atoms and the MoleAtoms and the Mole
A A collection termcollection term states states
a specific number of a specific number of
items.items.
• 1 dozen donuts 1 dozen donuts
= 12 donuts= 12 donuts
• 1 ream of paper 1 ream of paper
= 500 = 500 sheetssheets
• 1 case 1 case = 24 cans= 24 cans
Atoms and the MoleAtoms and the Mole
A A molemole is (a collection number) the amount of a is (a collection number) the amount of a
substance that containssubstance that contains
• the same number of particles (atoms, the same number of particles (atoms, molecules, ions, protons, electrons, etc.) as molecules, ions, protons, electrons, etc.) as there are carbon atoms in 12 g of carbon-12 there are carbon atoms in 12 g of carbon-12 isotopeisotope
• 1 mol = 6.022 x 101 mol = 6.022 x 102323 particles particles (Avogadro’s (Avogadro’s number). Amadeo Avogadronumber). Amadeo Avogadro
• The number is referred to the atomic mass The number is referred to the atomic mass assignedassigned to carbon-12 isotope. to carbon-12 isotope.
Atoms and the MoleAtoms and the Mole
1 mole of …1 mole of … Number of particlesNumber of particles
1 mole C 1 mole C = 6.022 x 10 = 6.022 x 102323 C atoms C atoms
1 mole Na 1 mole Na = 6.022 x 10 = 6.022 x 102323 Na atoms Na atoms
1 mole Au1 mole Au = 6.022 x 10 = 6.022 x 102323 Au atoms Au atoms
1 mole electrons = 6.022 x 101 mole electrons = 6.022 x 102323 electrons electrons
1 mole H1 mole H22OO = 6.022 x 10 = 6.022 x 102323 H H22O moleculesO molecules
1 mole Na1 mole Na++ = 6.022 x 10 = 6.022 x 102323 Na Na++ ions ions
Molar MassMolar MassThe The molar massmolar mass of any element is the mass in of any element is the mass in
grams of 6.022 x 10grams of 6.022 x 102323 atoms of that element, atoms of that element,
i.e., one i.e., one molemole of the element. of the element.
Molar massMolar mass is abbreviated is abbreviated MM, has units of , has units of
grams per mole grams per mole (g/mol),(g/mol), and is numerically and is numerically
equal to the atomic weight of the element equal to the atomic weight of the element ((periodic tableperiodic table))..
Molar mass of Na Molar mass of Na = 22.990 g/mol= 22.990 g/mol
Molar mass of Cl Molar mass of Cl = 35.453 g/mol= 35.453 g/mol
Molar mass of O Molar mass of O = 15.999 g/mol= 15.999 g/mol
Conversion factorsConversion factors Avogadro’s number Avogadro’s number 6.022 x 106.022 x 102323 can be written as can be written as
equalities and conversion factors.equalities and conversion factors.Equality:Equality:1 mole = 6.022 x 101 mole = 6.022 x 102323 particles = molar mass (g) particles = molar mass (g)Conversion Factors: particles = atoms or moleculesConversion Factors: particles = atoms or molecules6.022 x 106.022 x 102323 particles particles and and 1 mole 1 mole 1 mole1 mole 6.022 x 10 6.022 x 102323 particles particles
6.022 x 106.022 x 102323 particles particles and and molar mass (g) molar mass (g) molar mass (g) molar mass (g) 6.022 x 10 6.022 x 102323 particles particles
1 mole 1 mole and and molar mass (g) molar mass (g) molar mass (g) molar mass (g) 1 mole 1 mole
Converting moles Converting moles ↔↔ mass mass Moles to mass Mass to molesMoles to mass Mass to moles g 1 molg 1 molmoles moles x x ──────── = grams = grams gg x x ────= moles────= moles 1 mol grams 1 mol grams
The The molar massmolar mass as conversion factors as conversion factors
What is the mass of silicon represented by What is the mass of silicon represented by
0.250 moles of this element? 0.250 moles of this element? MM of Si = 28.086 of Si = 28.086 28.09 g g/mol 28.09 g g/mol
0.250 moles 0.250 moles x x ──────────── = 7.02 g Si = 7.02 g Si 1 mol1 mol
How many moles of manganese are 19.36 g ofHow many moles of manganese are 19.36 g of
that metal? that metal? MM of Mn = 54.938 g/mol of Mn = 54.938 g/mol 1 mol 1 mol 19.36 g 19.36 g x x ────────── = 0.352384 = = 0.352384 = 0.35240.3524 moles moles
54.938 g 4 SF54.938 g 4 SF
How many atoms of calcium are in 4.008 g ofHow many atoms of calcium are in 4.008 g of
that metal? that metal? MM of Ca = 40.08 g/mol of Ca = 40.08 g/mol
1 mol 6.022 x 101 mol 6.022 x 102323 atoms atoms 4.008 g 4.008 g x x ──────────── x x ────────────────────────── 40.08 g 1 mol40.08 g 1 mol
= 6.022 x 10= 6.022 x 102222 Ca atoms Ca atoms
The density of Au is 19.32 g/cmThe density of Au is 19.32 g/cm33. What is the . What is the volume of a piece of gold that contains 2.6 x 10volume of a piece of gold that contains 2.6 x 102424 atoms? If the piece of metal is a square with a atoms? If the piece of metal is a square with a thickness of 0.10 cm, what is the length (in cm) of thickness of 0.10 cm, what is the length (in cm) of one side of the square? one side of the square? AW = 196.97 g/molAW = 196.97 g/mol
196.97 g Au196.97 g Au2.6 x 102.6 x 102424 atoms Au atoms Au x x ──────────────────────── = 850 g Au = 850 g Au 6.022 x 106.022 x 102323 atoms atoms
1 cm1 cm33 850 g Au850 g Au x x ──────────────── = 44 cm = 44 cm33 Au Au 19.32 g Au19.32 g Au side = side = ll thickness (th)thickness (th)
V = th x A = th x V = th x A = th x ll22 A = area = A = area = ll22
l l = = SQRT SQRT (V/th) = (V/th) = SQRT SQRT (44 cm(44 cm33 / 0.10 cm) = 21 cm / 0.10 cm) = 21 cm
What is the average mass of one What is the average mass of one germanium atom? germanium atom? MM Ge = 72.59 g/mol Ge = 72.59 g/mol
Here we have to divide the mass of a Here we have to divide the mass of a mole by the number of atoms in that mole by the number of atoms in that mole.mole.
1 mole Ge = 72.59 g = 6.02 x 101 mole Ge = 72.59 g = 6.02 x 102323 atoms atoms
72.59 g Ge 1 mol Ge g Ge72.59 g Ge 1 mol Ge g Ge ─────── ─────── x x ────────────────────────── = 1.205 x10 = 1.205 x10-22-22 ────────── 1 mol Ge 6.022 x101 mol Ge 6.022 x102323 atoms Ge atom Ge atoms Ge atom Ge
0.0000000000000000000001205 g !!!!!!!0.0000000000000000000001205 g !!!!!!!
Periodic Table(*)Periodic Table(*)• a listing of the elements arranged according a listing of the elements arranged according
to their chemical and physical propertiesto their chemical and physical properties• elements are arranged according to similar elements are arranged according to similar
properties. properties. • Groups or families Groups or families contain elements with contain elements with
similar properties in vertical similar properties in vertical columnscolumns..
• periodsperiods are horizontal are horizontal rowsrows of elements. of elements. Every period has a number (row) from 1 Every period has a number (row) from 1 through 7.through 7.
(*) originally Mendeleev by (*) originally Mendeleev by atomic massatomic mass (1869), (1869), later Moseley by later Moseley by increasing atomic numberincreasing atomic number (1913).(1913).
Periodic TablePeriodic Table
• referred to by number or top elementreferred to by number or top element• some have names: some have names: The Representative ElementsThe Representative Elements• alkali metals - group 1Aalkali metals - group 1A• alkaline earth metals - group 2Aalkaline earth metals - group 2A• noble gases - group 8Anoble gases - group 8A• halogens - group 7Ahalogens - group 7A• chalcogens - group 6Achalcogens - group 6A• pnictogens - group 5Apnictogens - group 5A
GroupsGroups
Group 1A(1), the Group 1A(1), the alkali metalsalkali metals, includes , includes lithium, sodium, potassium, rubidium, lithium, sodium, potassium, rubidium, cesium, and franciumcesium, and francium
Alkali MetalsAlkali Metals
Group 7A(17) Group 7A(17) the the halogenshalogens, , includes includes fluorine, fluorine, chlorine, chlorine, bromine, and bromine, and iodine.iodine.
HalogensHalogens
Representative ElementsRepresentative Elements
1
Cr98
H
Li
Na
K
Rb
Cs
Fr
3
11
19
37
55
87
1.008
6.941
22.99
39.10
85.47
132.9
4
12
20
38
56
88
9.012
24.31
40.08
87.62
137.3
Be
Mg
Ca
Sr
Ba
Ra
21
39
57
89
44.96
88.91
138.9
Sc
Y
La
Ac
22
40
72
104
47.88
91.22
178.5
Ti
Zr
Hf
Unq
23
41
73
105
50.94
92.91
180.9
V
Nb
Ta
Unp
24
42
74
106
52.00
95.94
183.8
Mo
W
Unh
25
43
75
54.94
186.2
Mn
Tc
Re
Fe
Ru
Os
26
44
76
55.85
101.1
190.2
27 28 29 30
58.93 58.69 63.55 65.39Co Ni Cu Zn
Rh Pd Ag Cd
Ir Pt Au Hg
45 46 47 48
77 78 79 80102.9 106.4 107.9 112.4
192.2 195.1 200.6197.0
2
5 6 7 8 9 10
13 14 15 16 17 18
31 32 33 34 35 36
49 50 51 52 53 54
81 82 83 84 85 86
4.003
10.81 12.01 14.01 16.00 19.00 20.18
26.98 28.09 30.97 32.07 35.45 39.95
69.72 72.59 74.92 78.96 79.90 83.80
114.8 118.7 121.8 127.6 126.9 131.3
204.4 207.2 209.0
He
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Cr
11A
2A
3B 4B 5B 6B 7B 8B 1B 2B
3A 4A 5A 6A 7A
8A
58 59 60 61 62 63 64 65 66 67 68 69 70 71
90 91 92 93 94 95 96 97 98 99 100 101 102 103140.1 140.9 144.2 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0
232.0 238.0
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Fm Md No LwTh Pa U Np Pu Am Cm Bk Cf Es
(223) (226) (227) (257) (260) (263)
(210) (210) (222)
(257)(254)(256)(253)(254)(249)(247)(243)(242)(237) (247)(231)
(147)
(98)
107 108 109Uns Uno Une(262) (265) (266)
1
2
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
8B8B
Transition ElementsTransition Elements
1
Cr98
H
Li
Na
K
Rb
Cs
Fr
3
11
19
37
55
87
1.008
6.941
22.99
39.10
85.47
132.9
4
12
20
38
56
88
9.012
24.31
40.08
87.62
137.3
Be
Mg
Ca
Sr
Ba
Ra
21
39
57
89
44.96
88.91
138.9
Sc
Y
La
Ac
22
40
72
104
47.88
91.22
178.5
Ti
Zr
Hf
Unq
23
41
73
105
50.94
92.91
180.9
V
Nb
Ta
Unp
24
42
74
106
52.00
95.94
183.8
Mo
W
Unh
25
43
75
54.94
186.2
Mn
Tc
Re
Fe
Ru
Os
26
44
76
55.85
101.1
190.2
27 28 29 30
58.93 58.69 63.55 65.39Co Ni Cu Zn
Rh Pd Ag Cd
Ir Pt Au Hg
45 46 47 48
77 78 79 80102.9 106.4 107.9 112.4
192.2 195.1 200.6197.0
2
5 6 7 8 9 10
13 14 15 16 17 18
31 32 33 34 35 36
49 50 51 52 53 54
81 82 83 84 85 86
4.003
10.81 12.01 14.01 16.00 19.00 20.18
26.98 28.09 30.97 32.07 35.45 39.95
69.72 72.59 74.92 78.96 79.90 83.80
114.8 118.7 121.8 127.6 126.9 131.3
204.4 207.2 209.0
He
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Cr
11A
2A
3B 4B 5B 6B 7B 8B 1B 2B
3A 4A 5A 6A 7A
8A
58 59 60 61 62 63 64 65 66 67 68 69 70 71
90 91 92 93 94 95 96 97 98 99 100 101 102 103140.1 140.9 144.2 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0
232.0 238.0
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Fm Md No LwTh Pa U Np Pu Am Cm Bk Cf Es
(223) (226) (227) (257) (260) (263)
(210) (210) (222)
(257)(254)(256)(253)(254)(249)(247)(243)(242)(237) (247)(231)
(147)
(98)
107 108 109Uns Uno Une(262) (265) (266)
1
2
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
8B8B
Colors of solutions of Colors of solutions of Transition Metal CompoundsTransition Metal Compounds
Inner Transition ElementsInner Transition Elements
1
Cr98
H
Li
Na
K
Rb
Cs
Fr
3
11
19
37
55
87
1.008
6.941
22.99
39.10
85.47
132.9
4
12
20
38
56
88
9.012
24.31
40.08
87.62
137.3
Be
Mg
Ca
Sr
Ba
Ra
21
39
57
89
44.96
88.91
138.9
Sc
Y
La
Ac
22
40
72
104
47.88
91.22
178.5
Ti
Zr
Hf
Unq
23
41
73
105
50.94
92.91
180.9
V
Nb
Ta
Unp
24
42
74
106
52.00
95.94
183.8
Mo
W
Unh
25
43
75
54.94
186.2
Mn
Tc
Re
Fe
Ru
Os
26
44
76
55.85
101.1
190.2
27 28 29 30
58.93 58.69 63.55 65.39Co Ni Cu Zn
Rh Pd Ag Cd
Ir Pt Au Hg
45 46 47 48
77 78 79 80102.9 106.4 107.9 112.4
192.2 195.1 200.6197.0
2
5 6 7 8 9 10
13 14 15 16 17 18
31 32 33 34 35 36
49 50 51 52 53 54
81 82 83 84 85 86
4.003
10.81 12.01 14.01 16.00 19.00 20.18
26.98 28.09 30.97 32.07 35.45 39.95
69.72 72.59 74.92 78.96 79.90 83.80
114.8 118.7 121.8 127.6 126.9 131.3
204.4 207.2 209.0
He
B C N O F Ne
Al Si P S Cl Ar
Ga Ge As Se Br Kr
In Sn Sb Te I Xe
Tl Pb Bi Po At Rn
Cr
11A
2A
3B 4B 5B 6B 7B 8B 1B 2B
3A 4A 5A 6A 7A
8A
58 59 60 61 62 63 64 65 66 67 68 69 70 71
90 91 92 93 94 95 96 97 98 99 100 101 102 103140.1 140.9 144.2 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0
232.0 238.0
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Fm Md No LwTh Pa U Np Pu Am Cm Bk Cf Es
(223) (226) (227) (257) (260) (263)
(210) (210) (222)
(257)(254)(256)(253)(254)(249)(247)(243)(242)(237) (247)(231)
(147)
(98)
107 108 109Uns Uno Une(262) (265) (266)
1
2
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
8B8B
• rows = periodsrows = periods
• gradual transition in gradual transition in properties from metallic to properties from metallic to nonmetallic moving from left nonmetallic moving from left to right across a periodto right across a period
MetalsMetals• Malleable: can be hammered or pressed Malleable: can be hammered or pressed
into new shapes (coins, rings, etc.)into new shapes (coins, rings, etc.)• Ductile: can be pressed, beaten, or drawn Ductile: can be pressed, beaten, or drawn
into shape when cold (wires, such as Cu)into shape when cold (wires, such as Cu)• solid at room temperature (except for Hg)solid at room temperature (except for Hg)• lusterluster• photoelectric effect (ephotoelectric effect (e–– emission due to emission due to
light)light)• thermionic effect (ethermionic effect (e–– emission due to heat) emission due to heat)• readily readily loselose electrons electrons• good thermal and electrical conductorsgood thermal and electrical conductors
NonmetalsNonmetals
• solid, liquid, or gassolid, liquid, or gas
• brittle if solid (fracture)brittle if solid (fracture)
• non-malleable, non-ductilenon-malleable, non-ductile
• thermal and electrical insulatorsthermal and electrical insulators
• do not exhibit photoelectric effectdo not exhibit photoelectric effect
• do not exhibit thermionic effectdo not exhibit thermionic effect
• readily readily gaingain electrons electrons
Metalloids (Semimetals)Metalloids (Semimetals)
• properties intermediate to those of properties intermediate to those of metals and nonmetalsmetals and nonmetals
• are located around the solid ladder are located around the solid ladder between metals and non-metals in between metals and non-metals in periodic tableperiodic table
• B, Si, Ge, As, Sb, Te, Po, AtB, Si, Ge, As, Sb, Te, Po, At
Noble gasesNoble gases
• Are the least reactive elementsAre the least reactive elements
• Are gases, none-abundant on Earth, Are gases, none-abundant on Earth, but He is the second in the universe but He is the second in the universe after hydrogen after hydrogen
• Neon in advertising signs Neon in advertising signs
• Some lasers are made of He, Ar, KrSome lasers are made of He, Ar, Kr
Learning CheckLearning Check
Identify each of the following elements as Identify each of the following elements as 1) metal 1) metal 2) nonmetal 3) metalloid 2) nonmetal 3) metalloid
A. sodiumA. sodium ________B. chlorineB. chlorine ________C. silicon C. silicon ________D. ironD. iron ________E. carbonE. carbon ________F. antimony ____F. antimony ____
Learning CheckLearning Check
Match the elements to the description.Match the elements to the description.
A. Metals in Group 4A(14) A. Metals in Group 4A(14) 1) Sn, Pb 2) C, Si 3) C, Si, Ge, Sn1) Sn, Pb 2) C, Si 3) C, Si, Ge, Sn
B. Nonmetals in Group 5A(15)B. Nonmetals in Group 5A(15) 1) As, Sb, Bi 1) As, Sb, Bi 2) N, P 2) N, P 3) N, P, As, Sb 3) N, P, As, Sb
C. Metalloids in Group 4A(14)C. Metalloids in Group 4A(14) 1) C, Si, Ge, 2) Si, Ge 3) Si, Ge, Sn, Pb1) C, Si, Ge, 2) Si, Ge 3) Si, Ge, Sn, Pb
Learning CheckLearning CheckThe elements magnesium and calcium are in what The elements magnesium and calcium are in what group? group? a. alkali metals b. alkaline earth metalsa. alkali metals b. alkaline earth metalsc. halogens d. noble gasesc. halogens d. noble gases
Which elements are nonmetals? Which elements are nonmetals? a. sodium and potassiuma. sodium and potassiumb. magnesium and bariumb. magnesium and bariumc. boron and aluminum d. carbon and brominec. boron and aluminum d. carbon and bromine
Identify the period number for the row that ends in Identify the period number for the row that ends in argon. argon. a. Period 1 b. Period 2 c. Period 3 d.Period 4a. Period 1 b. Period 2 c. Period 3 d.Period 4
Learning CheckLearning CheckWhich statement is characteristic of metals?Which statement is characteristic of metals?
A. They are shiny. A. They are shiny. B. They are poor conductors of electricity. B. They are poor conductors of electricity. C. They melt at high temperatures. C. They melt at high temperatures.
a. statement A only b. statements A and B only a. statement A only b. statements A and B only c. statements A, B, and Cc. statements A, B, and Cd. statements A and C onlyd. statements A and C only
Which statement is false?Which statement is false?
A. Potassium is an alkali metal. A. Potassium is an alkali metal. B. Strontium is an alkaline earth metal. B. Strontium is an alkaline earth metal. C. Argon is a noble gas. C. Argon is a noble gas. D. Zinc in a halogen. D. Zinc in a halogen.
Learning CheckLearning Check
What is the right order of increasing metallic What is the right order of increasing metallic
character for the elements Rb, F, P, Ga?character for the elements Rb, F, P, Ga?
Rb < F < P < GaRb < F < P < Ga
P < F < Rb < GaP < F < Rb < Ga
Ga< Rb < P < FGa< Rb < P < F
F < P < Ga < RbF < P < Ga < Rb
Learning CheckLearning CheckHow many atoms are in 1.50 mol Na?How many atoms are in 1.50 mol Na?
A.1.50 b. 9.03x10A.1.50 b. 9.03x102323 c. 3.00 d. 2.49x10 c. 3.00 d. 2.49x10-24-24 e. 345 e. 345
6.0226.02210102323 atoms atoms 1.50 mol 1.50 mol ──────────── = ──────────── = 9.03 x 109.03 x 102323 atoms atoms 1 mol1 mol
How many moles of Ar in 5.22 x 10How many moles of Ar in 5.22 x 102222 atoms of this atoms of this
noble gas? a. 11.5 b. 0.0867 c. 1.15x10noble gas? a. 11.5 b. 0.0867 c. 1.15x102222
d. 8.67x10d. 8.67x102323 e. 3.14 x e. 3.14 x10104646
1 mol1 mol 5.22 x 105.22 x 102222 atoms atoms ──────────── = 0.0867 mol──────────── = 0.0867 mol 6.0226.02210102323 atoms atoms
Learning CheckLearning Check
What is the mass (grams) of one atom of Na?What is the mass (grams) of one atom of Na?
a. 22.99 b. 0.04350 c. 3.818 x 10a. 22.99 b. 0.04350 c. 3.818 x 10 2323 b. 2.619x10 b. 2.619x102222
22.99 g22.99 g1 mol Na 1 mol Na ─────────── = ─────────── = 3.818 x 103.818 x 102323 g/atomg/atom 6.0226.02210102323 atoms atoms