Chapter Chapter 66PeriodicityPeriodicity

Obj. Obj. 11…Periodic Law…Periodic Law• Elements on the periodic table (PT) are Elements on the periodic table (PT) are organizedorganizedby their physical and chemical properties.by their physical and chemical properties.

• Periodic LawPeriodic Law states that the phys. and chem. states that the phys. and chem. props. ofprops. ofelements are a ‘periodic function of their atomic #’. elements are a ‘periodic function of their atomic #’. (p+)(p+)

• As elements are placed in order of atomic #, As elements are placed in order of atomic #, patternspatternsof properties start to develop.of properties start to develop.

Obj. Obj. 22…Organization of …Organization of the PTthe PT• PT is based on work done by Mendeleev and PT is based on work done by Mendeleev and

Moseley.Moseley.

• Both arranged elements in rows and columns.Both arranged elements in rows and columns.

• Mendeleev – according to atomic mass.Mendeleev – according to atomic mass.

• Moseley – according to atomic #s (**modern Moseley – according to atomic #s (**modern PT**).PT**).

Obj. Obj. 22 cont… cont…• Horizontal rows = Horizontal rows = periodsperiods = energy level = energy level

• Vertical columns = Vertical columns = groupsgroups or or familiesfamilies = valence = valence ee--..• groups are represented by…groups are represented by…

- single # (1-18)- single # (1-18)- roman numeral and letter (A or B)- roman numeral and letter (A or B)

• ‘ ‘A’ groups = A’ groups = representative elementsrepresentative elements ( (ss and and pp orbitals)orbitals)

Obj. Obj. 22 cont… cont…

- group # = valence - group # = valence ee--..

• ‘ ‘B’ groups = B’ groups = transition metalstransition metals ( (dd orbitals) orbitals)

• ‘ ‘LanthanideLanthanide’ & ‘’ & ‘ActinideActinide’ series = ’ series = ff orbitalsorbitals- no group #- no group #

- 2 valence e- (‘s’ orbital)- 2 valence e- (‘s’ orbital)

Obj. Obj. 33…Location of …Location of GroupsGroups

• Metals are to the Metals are to the left left of the zig-zag. of the zig-zag.

METALMETALS S

METALMETALS S • Non-metals are to the Non-metals are to the right right of the zig-zag. of the zig-zag.

(+ H) (+ H)

NON-NON-METALS METALS

• Metalloids touch the zig-zag! Metalloids touch the zig-zag!

METALLOIDSMETALLOIDS

Obj. Obj. 33 cont… cont…

• Noble Gases = group 8A (He – Rn)Noble Gases = group 8A (He – Rn)

NO

BL

E G

AS

ES

NO

BL

E G

AS

ES

• Halogens = group 7A (F – At)Halogens = group 7A (F – At)

HA

LO

GE

NS

HA

LO

GE

NS

• Lanthanide Series = orbital 4f (Ce – Lu)Lanthanide Series = orbital 4f (Ce – Lu)

LANTHANIDELANTHANIDE

• Actinide Series = orbital 5f (Th – Lr)Actinide Series = orbital 5f (Th – Lr)

ACTINIDEACTINIDE

• Transition Metals = ‘B’ groups or ‘d’ Transition Metals = ‘B’ groups or ‘d’ orbitalsorbitals

TRANSITION TRANSITION METALSMETALS

• Rare Earth Metals = Lanthanide Series (Ce Rare Earth Metals = Lanthanide Series (Ce – Lu)– Lu)

RARE EARTH METALSRARE EARTH METALS

• Alkali Metals = group 1A (Li – Fr)Alkali Metals = group 1A (Li – Fr)

AL

KA

LI

ME

TA

LS

AL

KA

LI

ME

TA

LS

• Alkaline Earth Metals = group 2A (Be – Ra)Alkaline Earth Metals = group 2A (Be – Ra)

AL

KA

LIN

E

EA

RT

HA

LK

AL

INE

E

AR

TH

• Representative Elements = ‘A’ groups = S & P Representative Elements = ‘A’ groups = S & P orbitalsorbitals

REPRESENTATIVE REPRESENTATIVE ELEMENTSELEMENTS

Obj. Obj. 44…Octet Rule…Octet Rule• valence e- are all e- in the ‘s’ and ‘p’ orbitals on valence e- are all e- in the ‘s’ and ‘p’ orbitals on thethehighest energy level.highest energy level.

• ‘ ‘s’ orbitals hold 2 e-.s’ orbitals hold 2 e-.

• ‘ ‘p’ orbitals hold 6 e-.p’ orbitals hold 6 e-.

• max. of 8 valence e- for any element! max. of 8 valence e- for any element!

• all Noble Gases (8A) (except He) have 8 all Noble Gases (8A) (except He) have 8 valence e-. valence e-. - - veryvery stable!!! (happy stable!!! (happy ) )

• all other elements on the PT want to be like all other elements on the PT want to be like group 8A! group 8A! - 8 valence e-- 8 valence e-

Obj. Obj. 44 cont… cont…• to get 8 valence e-to get 8 valence e-… … • metals (left side of PT) tend to metals (left side of PT) tend to loselose e-. e-.

• non-metals (right side of PT) tend to non-metals (right side of PT) tend to gaingain e-. e-. • METALS… METALS…

Magnesium (Z = Magnesium (Z = 12): 12):

two two options: options: - gain 6 - gain 6

e-e-- lose 2 - lose 2 e-e-

****- 12 p- 12 p++ and 10 e- and 10 e- ==- (+) ion = - (+) ion = cationcation

+2 charge+2 charge

oxidation oxidation # #

• NON - METALS… NON - METALS…

Chlorine (Z = 17): Chlorine (Z = 17):

two two options: options: - gain 1 - gain 1

e-e-- lose 7 - lose 7 e-e-

****

- 17 p- 17 p++ and 18 e- = and 18 e- =- (-) ion = - (-) ion = anionanion

Obj. Obj. 44 cont… cont…

-1 charge-1 charge

oxidation oxidation # #

*Halogens are the most reactive elements.

Obj. Obj. 44 cont… cont…• group by group… group by group…

IAIA IIAIIA B GroupsB Groups IIIAIIIA IVAIVA VAVA VIAVIA VIIAVIIA VIIIA VIIIA lose lose 1 e- 1 e-

+ 1 + 1

lose lose 2 e- 2 e-

+ 2 + 2

lose lose 2 e- 2 e-

+ 2 + 2

lose lose 3 e- 3 e-

+ 3 + 3

lose lose or or

gain 4 gain 4 e- e- +/- 4 +/- 4

gain gain 3 e- 3 e-

- 3 - 3

gain gain 2 e- 2 e-

- 2 - 2

gain gain 1 e- 1 e-

- 1 - 1

N/A N/A

0 0

Obj. Obj. 55…Outer e- …Outer e- ConfigurationConfiguration• practice… practice…

• who is… who is…

6s6s22 6p 6p55 Astatine (At) Astatine (At)

5s5s22 Strontium (Sr) Strontium (Sr)

5s5s2 2 4d4d55 Technetium (Tc) Technetium (Tc)

3s3s2 2 3p3p66 Argon (Ar)Argon (Ar)

Francium Francium (Fr) (Fr)

7s7s11

Tungsten Tungsten (W) (W)

6s6s2 2 5d5d44

Arsenic (As) Arsenic (As)

4s4s2 2 4p4p33

Krypton (Kr) Krypton (Kr)

4s4s2 2 4p4p66

Obj. Obj. 6 - 76 - 7…Vocab. and …Vocab. and TrendsTrends• ionization ionization

energyenergy: : energy needed to steal a valence e-energy needed to steal a valence e-

from a neutral atom.from a neutral atom.• increases as you move across a period. increases as you move across a period. - harder to steal from non-metals than metals- harder to steal from non-metals than metals

• increases as you move a group. increases as you move a group. - harder to steal from small atoms than large- harder to steal from small atoms than large- e- are closer to the nucleus in small atoms.- e- are closer to the nucleus in small atoms.

** Helium (He) has highest! ** Helium (He) has highest!

Obj. Obj. 6-76-7 cont… cont…• electronegativityelectronegativity: :

ability of an atom to attract ability of an atom to attract e-.e-.

• increases as you move across a period. increases as you move across a period. - non-metals need to gain e- to be stable.- non-metals need to gain e- to be stable.

• increases as you move a group. increases as you move a group. - small atoms attract e- easier b/c nucleus is close- small atoms attract e- easier b/c nucleus is close

to e- it is trying to steal!to e- it is trying to steal!

** Fluorine (F) has highest! ** Fluorine (F) has highest!

Obj. Obj. 6-76-7 cont… cont…• atomic radiusatomic radius: : distance from nucleus to valence distance from nucleus to valence

e-.e-.• increases as you move a group. increases as you move a group.

- more energy levels = larger radius.- more energy levels = larger radius.

• increases as you move across a period. increases as you move across a period.

- less e- = less attraction to nucleus.- less e- = less attraction to nucleus.

- ‘fluffy’- ‘fluffy’

- more e- = tighter atom.- more e- = tighter atom.

** Francium (Fr) is biggest! ** Francium (Fr) is biggest!

Obj. Obj. 6-76-7 cont… cont…• ionic radiusionic radius: : radius of an atom after it gains/loses radius of an atom after it gains/loses

e-.e-.• increases as you move a group. increases as you move a group.

- more energy levels = larger radius.- more energy levels = larger radius.

CATIONSCATIONS: : (metals: + (metals: + ions)ions)- lose e-, so cation is smaller than neutral atom.- lose e-, so cation is smaller than neutral atom.

ANIONSANIONS: : (non-metals: - ions)(non-metals: - ions)

- gain e-, so anion is larger than neutral atom.- gain e-, so anion is larger than neutral atom.

Obj. Obj. 6-76-7 cont… cont…• metallic metallic charactercharacter: :

ability of an atom to lose ability of an atom to lose e-.e-.• increases as you move across a period. increases as you move across a period.

- metals need to lose e- to be stable.- metals need to lose e- to be stable.

• increases as you move a group. increases as you move a group.

- larger atom = easier to lose e-.- larger atom = easier to lose e-.

- less attraction b/n nucleus and valence e-.- less attraction b/n nucleus and valence e-.

** Francium (Fr) is most active! ** Francium (Fr) is most active!

Obj. Obj. 6-76-7 cont… cont…• non-metallic characternon-metallic character: : ability of an atom to gain ability of an atom to gain

e-.e-.• increases as you move across a period. increases as you move across a period.

- non-metals need to gain e- to be stable.- non-metals need to gain e- to be stable.• increases as you move a group. increases as you move a group.

- smaller atom = easier to gain e-.- smaller atom = easier to gain e-.

- more attraction b/n nucleus and valence e- of- more attraction b/n nucleus and valence e- ofneighbor atom.neighbor atom.

** Fluorine (F) is most ** Fluorine (F) is most active! active!

Obj. Obj. 6-76-7 cont… cont…• ionization energyionization energy: :

• electronegativityelectronegativity: :

• atomic radiusatomic radius: :

• ionic radiusionic radius: :

• metallic charactermetallic character: :

• non-metallic characternon-metallic character: :

cation = smaller / anion = larger cation = smaller / anion = larger

Obj. Obj. 6-76-7 cont… cont…

• Oxidation #... See Objective 4 (Octet Rule)Oxidation #... See Objective 4 (Octet Rule)

• Outer e- configuration... See Outer e- configuration... See Objective 5Objective 5

Chapter 7Chapter 7 92 natural elements (all after U man-made)92 natural elements (all after U man-made)

* Groups 1A-8A = Representative Elements* Groups 1A-8A = Representative Elements* elements in a family(group) have same # valence * elements in a family(group) have same # valence e-e-* # & location of valence e- determine chemistry* # & location of valence e- determine chemistry* * metalsmetals tend to LOSE e- tend to LOSE e-

• metal reactivity increases ↓ a group and ← a metal reactivity increases ↓ a group and ← a periodperiod

* * nonmetalsnonmetals tend to GAIN e- tend to GAIN e-• nonmetal reactivity increases ↑ a group and → nonmetal reactivity increases ↑ a group and → a perioda period

Chapter 7Chapter 7““S” block elementsS” block elementsHydrogenHydrogen ( (hydrohydro = water + = water + genesgenes = to form) = to form)* 1 valence e- but doesn’t always behave like group 1A * 1 valence e- but doesn’t always behave like group 1A * can lose e- (like metals) or gain e- (like nonmetal)* can lose e- (like metals) or gain e- (like nonmetal)•3 natural isotopes: 3 natural isotopes:

protium- mass of 1, 0 neutrons, 99.985% of protium- mass of 1, 0 neutrons, 99.985% of all Hall H

deuterium- mass of 2, 1 neutron, deuterium- mass of 2, 1 neutron, •““heavy water” used in nuclear reactorsheavy water” used in nuclear reactors

tritium – mass of 3, radioactive, raretritium – mass of 3, radioactive, rare

Chapter 7Chapter 7

Group 1A: ALKALI METALGroup 1A: ALKALI METAL

* 1 valence e- ( Na = [Ne]3s1 , K = [Ar]4s1 , Rb = [Kr]5s1 )* 1 valence e- ( Na = [Ne]3s1 , K = [Ar]4s1 , Rb = [Kr]5s1 )* low densities, low melting pts, good conductors, * low densities, low melting pts, good conductors, soft enuf to be cut w/ a knifesoft enuf to be cut w/ a knife* react violently w/ H20 to form H2 gas & metal * react violently w/ H20 to form H2 gas & metal hydroxidehydroxide

(OH- makes a soln. alkaline or base)(OH- makes a soln. alkaline or base)* not usually found in “pure” form, so reactive they are * not usually found in “pure” form, so reactive they are always forming cmpds, esp like to react w/ halogensalways forming cmpds, esp like to react w/ halogens

Chapter 7Chapter 7Group 2A: ALKALINE EARTH METALSGroup 2A: ALKALINE EARTH METALS* 2 valence e- ( Be = [He]2s2, Mg = [Ne]3s2, Ca = [Ar]4s2 )* 2 valence e- ( Be = [He]2s2, Mg = [Ne]3s2, Ca = [Ar]4s2 )* less reactive than 1A but still make * less reactive than 1A but still make alkalinealkaline solns. solns.

react w/ acids to form H2 and metallic OH-react w/ acids to form H2 and metallic OH-* found in mineral ores (earths) * found in mineral ores (earths) Metal oxides don’t melt in fire, alchemists called them Metal oxides don’t melt in fire, alchemists called them earthsearthsBeBeMgMgCaCaSrSrBaBaRaRa

Chapter 7Chapter 7““P” block elements P” block elements Groups 3A – 8A Groups 3A – 8A3A Boron or Aluminum Family3A Boron or Aluminum Family* most lose 3 valence e- to form 3+ ions B =[He]2s22p1, Al * most lose 3 valence e- to form 3+ ions B =[He]2s22p1, Al =[Ne]3s23p1=[Ne]3s23p1

(except Th which loses only 1 “p” e- to form 1+ ion)(except Th which loses only 1 “p” e- to form 1+ ion)* less metallic than group 1 or 2, sometimes will* less metallic than group 1 or 2, sometimes will shareshare e- rather than give 3 away e- rather than give 3 awayBBAlAlGaGaIn, TlIn, Tl

Chapter 7Chapter 74A Carbon Group 4A Carbon Group

C nonmetal, Si & Ge metalloids, Sn & Pb metalsC nonmetal, Si & Ge metalloids, Sn & Pb metals* 4 e- in outer shell C = 1s22s22p2 Si = [Ne]3s23p2 Ge = * 4 e- in outer shell C = 1s22s22p2 Si = [Ne]3s23p2 Ge = [Ar]4s23d104p2[Ar]4s23d104p2* 4 is halfway pt of full octet, * 4 is halfway pt of full octet, could give 4 e- away (metallic) or add 4 e- (nonmetal)could give 4 e- away (metallic) or add 4 e- (nonmetal)

probably will probably will shareshareC 4 C 4 allotropes allotropes (forms) (forms) diamond diamond - nonmetal crystal- nonmetal crystal

Graphite Graphite - metalloid, solid lubricant, pencils, tire blacking- metalloid, solid lubricant, pencils, tire blacking Amorphous Amorphous - coal - coal buckeyballbuckeyball- sphere of C- sphere of C6060Si metalloid, transistors, computer chips, synthetic motor oils, Si metalloid, transistors, computer chips, synthetic motor oils, diodes (lights), lasers diodes (lights), lasers Ge metalloid, both Si and Ge are Ge metalloid, both Si and Ge are semiconductorssemiconductors Meaning:Meaning: insulators at lo temp, conductor at hi temp insulators at lo temp, conductor at hi tempSn and Pb are metals - not very reactive, good alloysSn and Pb are metals - not very reactive, good alloys

Pb + Sn = solder, Cu + Sn = bronzePb + Sn = solder, Cu + Sn = bronze

Chapter 7Chapter 7

5A: Nitrogen Group5A: Nitrogen GroupN & P nonmetals (gain e-), As & Sb metalloids, Bi metal (lose N & P nonmetals (gain e-), As & Sb metalloids, Bi metal (lose e-)e-)* 5 valence e-* 5 valence e-N can gain 3e to = 8, 78% of Earth’s atmosphereN can gain 3e to = 8, 78% of Earth’s atmosphereP 3 allotropesP 3 allotropesAsAsSbSbBi may lose 3 e- [Xe]6s24f145d106pBi may lose 3 e- [Xe]6s24f145d106p33

Chapter 7Chapter 7

6A: Oxygen Group6A: Oxygen Group* 6 valence e- O = 1s22s22p4 S = [Ne]3s23p4* 6 valence e- O = 1s22s22p4 S = [Ne]3s23p4O 2 allotropes O2 most abundant element on earthO 2 allotropes O2 most abundant element on earth

O3 ozoneO3 ozoneS 10 allotropesS 10 allotropesSeSeTeTePoPo

Chapter 7Chapter 7

7A: Halogens (7A: Halogens (halos = salt, gen = bornhalos = salt, gen = born))* 7 valence e-* 7 valence e-* most active of nonmetals, usually gain 1 e-* most active of nonmetals, usually gain 1 e-* always found in cmpds, never free* always found in cmpds, never free* combines most easily w/ a Group 1 or 2 metal* combines most easily w/ a Group 1 or 2 metal to form a “salt”to form a “salt”FFClClBrBrIIAtAtHH

Chapter 7Chapter 7

8A: Noble Gases 8A: Noble Gases * 8 e- in outer shell ( * 8 e- in outer shell ( fullfull s2p6s2p6 anan octetoctet - very stable - very stable))* found in free state, until 1962 no cmpds known * found in free state, until 1962 no cmpds known used to be called inert gases b/c didn’t reactused to be called inert gases b/c didn’t reactHeHeNeNeArArKrKrXeXe

Chapter 7Chapter 7Transition Metals “B” groupsTransition Metals “B” groups* e- going into the d subshell* e- going into the d subshell ((full and half full d subshell more stable)full and half full d subshell more stable)* metallic luster, good conductors, malleable, * metallic luster, good conductors, malleable, many have variable chargesmany have variable charges* can form cmpds with nonmetals* can form cmpds with nonmetals* often form alloys w/ other metals * often form alloys w/ other metals ((alloys are mixtures not cmpdsalloys are mixtures not cmpds))examples:examples:FeFeCuCuCoCoCrCrZnZn