Chapter 6 The Periodic Table & Periodic Law. Section 6.1—Development of the Modern Periodic Table...

Chapter 6Chapter 6

The Periodic Table & Periodic The Periodic Table & Periodic LawLaw

Section 6.1—Development of Section 6.1—Development of the Modern Periodic Tablethe Modern Periodic Table

In the late 1790s, French scientist In the late 1790s, French scientist Antoine Lavoisier compiled a list of Antoine Lavoisier compiled a list of elements known at the time, 23 of elements known at the time, 23 of them. them.


In 1864, English chemist John In 1864, English chemist John Newlands proposed that the Newlands proposed that the elements be arranged in increasing elements be arranged in increasing atomic mass, and if so, their atomic mass, and if so, their properties repeated every 8th properties repeated every 8th element. element.


He called this the law of octaves, He called this the law of octaves, which was later disproved because it which was later disproved because it did not work for all of the elements,did not work for all of the elements,

After a few years passed, it was After a few years passed, it was shown that he was basically correct; shown that he was basically correct; the properties of the elements do the properties of the elements do repeat in a periodic way. repeat in a periodic way.

In 1869, Russian chemist Dmitri In 1869, Russian chemist Dmitri Mendeleev arranged the elements by Mendeleev arranged the elements by increasing atomic mass into columns increasing atomic mass into columns with similar properties into the 1st with similar properties into the 1st periodic table. periodic table.


He left blank He left blank spaces for spaces for undiscovered undiscovered elements of which elements of which he predicted he predicted scandium, gallium, scandium, gallium, & germanium. & germanium.


In 1913, English chemist Henry In 1913, English chemist Henry Moseley noted that if you arrange Moseley noted that if you arrange the elements in order of the number the elements in order of the number of protons they contain instead of of protons they contain instead of atomic masses, they result in a clear atomic masses, they result in a clear periodic pattern of properties. periodic pattern of properties.


The statement that there is a The statement that there is a periodic repetition of chemical & periodic repetition of chemical & physical properties of the elements physical properties of the elements when they are arranged by when they are arranged by increasing atomic number is called increasing atomic number is called the the periodic law.periodic law.


The boxes are arranged into a series The boxes are arranged into a series of columns called groups, or families, of columns called groups, or families, and rows called periods. and rows called periods.

The representative elements (the A The representative elements (the A group) are often referred to as the group) are often referred to as the main group because they possess a main group because they possess a wide range of chemical & physical wide range of chemical & physical properties. properties.

The transition elements are the The transition elements are the elements in the B group. elements in the B group.


There are 3 main classifications for There are 3 main classifications for the elements—metals, nonmetals, the elements—metals, nonmetals, & metalloids.& metalloids.


Metals—elements that are generally Metals—elements that are generally shiny when smooth & clean, solid at shiny when smooth & clean, solid at room temperature, & good room temperature, & good conductors of heat & electricity. conductors of heat & electricity. Most are ductile & malleable.Most are ductile & malleable.

They also lose electronsThey also lose electrons


– Metals located on left of stair-step Metals located on left of stair-step line(except for hydrogen) line(except for hydrogen)

– The group 1A elements are known as The group 1A elements are known as the alkali metalsthe alkali metals

– The group 2A elements are known as The group 2A elements are known as the alkaline earth metalsthe alkaline earth metals

Both are chemically reactive, with the Both are chemically reactive, with the alkali being more reactivealkali being more reactive

– The transition elements are divided into The transition elements are divided into the transition metals & the inner the transition metals & the inner transition metalstransition metals

– The inner transition metals are the The inner transition metals are the lanthanide & actinide series that make lanthanide & actinide series that make up the bottom of the periodic chart. up the bottom of the periodic chart.


Nonmetals—are elements that are Nonmetals—are elements that are generally gases or brittle, dull-looking generally gases or brittle, dull-looking solids. They are poor conductors of heat solids. They are poor conductors of heat & electricity. The nonmetals occupy the & electricity. The nonmetals occupy the upper right side of the periodic table.upper right side of the periodic table.

– The only nonmetal that is liquid at room temp The only nonmetal that is liquid at room temp is bromine. is bromine.

– The highly reactive 7A group is known The highly reactive 7A group is known as the halogens.as the halogens.

– The highly unreactive 8A group are The highly unreactive 8A group are known as the noble gases.known as the noble gases.

– Gain e-Gain e-

NonmetalsNonmetals


Metalloids—are elements with Metalloids—are elements with physical & chemical properties of physical & chemical properties of both metals & nonmetals. both metals & nonmetals.

– These elements border the stair-step These elements border the stair-step line.line.

stopstop

Section 6.2—Classification Section 6.2—Classification of the Elementsof the Elements

The elements are organized by their The elements are organized by their electron configuration.electron configuration.

Atoms in the same group have Atoms in the same group have similar chemical properties because similar chemical properties because they have the same number of they have the same number of valence electrons. valence electrons.


Group 1 elements have a Group 1 elements have a configuration of sconfiguration of s11..

Group 2 elements have a Group 2 elements have a configuration of sconfiguration of s22. .

The The energy levelenergy level of an element’s of an element’s valence electrons indicates the valence electrons indicates the periodperiod on the periodic table in which on the periodic table in which it is found.it is found.


[Ar]4s[Ar]4s223d3d10104p4p1 1 Gallium Gallium

belongs to the 4belongs to the 4thth period. period.


1s1s22 2s 2s22 2p 2p66 3s 3s22 3p 3p66 4s 4s22 3d 3d1010 4p 4p66 5s 5s22

Period?Period? 55 Group?Group? 2A2A Element?Element? StrontiumStrontium

Examples. Give the Examples. Give the element.element.

……4s4s22

……6s6s11

……2s2s22

……1s1s22


Remember electron dot??? Does not apply Remember electron dot??? Does not apply to the transition elements.to the transition elements.

Group 1 Group 1 valence electrons = 1 valence electrons = 1 Group 2 Group 2 valence electrons = 2 valence electrons = 2 Group 13 Group 13 valence electrons = 3 valence electrons = 3 Group 14 Group 14 valence electrons = 4 valence electrons = 4 Group 15 Group 15 valence electrons = 5 valence electrons = 5 Group 16 Group 16 valence electrons = 6 valence electrons = 6 Group 17 Group 17 valence electrons = 7 valence electrons = 7 Group 18 Group 18 valence electrons = 8 (exception is He) valence electrons = 8 (exception is He)

How many valence e-?How many valence e-?

Silicon?Silicon? Calcium?Calcium? Bromine?Bromine? Krypton?Krypton? Potassium?Potassium? Helium?Helium?


Remember the orbitals??? Remember the orbitals???

s, p, d, & fs, p, d, & f


s-block elementss-block elements Group 1 & 2 Group 1 & 2 elements & helium.elements & helium.– Valence electrons only in “s” orbitalsValence electrons only in “s” orbitals

p-block elementsp-block elements Groups 13-18 Groups 13-18 (except He)(except He)– valence electrons are filling or have valence electrons are filling or have

filled the “p” orbitalsfilled the “p” orbitals– Group 18 Group 18 noble gases noble gases s & p s & p

orbitals are completely filled & are very orbitals are completely filled & are very stable elementsstable elements

Give the elementGive the element

……3p3p11

……4p4p66

……5p5p22

……6p6p22

……3s3s22

……3d3d1010


d-block elementsd-block elements Groups 3-12, Groups 3-12, the transition metalsthe transition metals– Period 4 is filling the 3d orbitalPeriod 4 is filling the 3d orbital– Period 5 is filling the 4d orbitalPeriod 5 is filling the 4d orbital– Period 6 is filling the 5d orbitalPeriod 6 is filling the 5d orbital

f-block elementsf-block elements inner inner transitional metals; lanthanide & transitional metals; lanthanide & actinide seriesactinide series– Period 6 is filling the 4f orbitalPeriod 6 is filling the 4f orbital– Period 7 is filling the 5f orbitalPeriod 7 is filling the 5f orbital

Give the elementGive the element

……3d3d22

……5d5d99

……4d4d1010

……5f5f22

……4f4f11

……5f5f11

Section 6.3—Periodic TrendsSection 6.3—Periodic Trends

Trends describe predictable changes Trends describe predictable changes in properties of the elements as you in properties of the elements as you move across a period or down a move across a period or down a group.group.

Atomic Radius (Atomic Size)Atomic Radius (Atomic Size)– There is a general decrease in atomic There is a general decrease in atomic

radii as you move across a period.radii as you move across a period.– There is an increase as you move down There is an increase as you move down

a group.a group.

C or N, which is larger? C or N, which is larger? CC Ca or Mg, which is smaller?Ca or Mg, which is smaller? MgMg Fr or Ra, which is larger?Fr or Ra, which is larger? FrFr

Ionization energy is the amount of Ionization energy is the amount of energy needed to remove an energy needed to remove an electron.electron.


– A high ionization energy indicates the A high ionization energy indicates the atom has a strong hold on its electrons. atom has a strong hold on its electrons.

– As you go across a period, the ionization As you go across a period, the ionization energy increases. energy increases.


As you go down a group, the As you go down a group, the ionization energy decreases. ionization energy decreases.


ElectronegativityElectronegativity– Electronegativity indicates the ability of Electronegativity indicates the ability of

atoms to attract electrons in a chemical atoms to attract electrons in a chemical bond. bond.


– Electronegativity is based on a scale of Electronegativity is based on a scale of 0-4. F- most electronegative element. 0-4. F- most electronegative element. Fr- least electronegative element. Fr- least electronegative element.

– Electronegativity increases as you go Electronegativity increases as you go across a period. across a period.

– Electronegativity decreases as you go Electronegativity decreases as you go down a group. down a group.

Electronegativity questionsElectronegativity questions

Which is more likely to get an Which is more likely to get an electron between…electron between…– Phosphorus & Arsenic?Phosphorus & Arsenic?– Magnesium & Silicon?Magnesium & Silicon?– Chlorine & Argon?Chlorine & Argon?

Chapter 6 The Periodic Table & Periodic Law. Section 6.1—Development of the Modern Periodic Table...

Documents

Transcript of Chapter 6 The Periodic Table & Periodic Law. Section 6.1—Development of the Modern Periodic Table...