atomic structure nuclear and electronic organization

Atomic StructureAtomic Structure

Nuclear and Electronic Nuclear and Electronic OrganizationOrganization

AtomsAtoms

Notion dates from Notion dates from caca 400 BCE - 400 BCE - DemocritusDemocritus

Notion lay dormat 2200 years until Notion lay dormat 2200 years until early 1800’s - John Daltonearly 1800’s - John Dalton

John DaltonJohn Dalton

1766-1844

Dalton’s TheoryDalton’s Theory

Explained Conservation of Mass in Explained Conservation of Mass in chemical and physical changeschemical and physical changes

Accounted for differences between Accounted for differences between elements and compoundselements and compounds

Accounted for constant composition Accounted for constant composition of compound substances. Water, of compound substances. Water, egeg, always 88.9% oxygen and , always 88.9% oxygen and 11.1% hydrogen11.1% hydrogen

AtomsAtoms

Incredibly smallIncredibly small Sub-microscopicSub-microscopic Yet much is understood, Yet much is understood,

measurable of measurable of sub-atomicsub-atomic structure structure

Two Major Zones or Two Major Zones or RegionsRegions

NucleusNucleus– Dense, central coreDense, central core– Almost all of the atomic massAlmost all of the atomic mass– only about 1-trillionth of the space or only about 1-trillionth of the space or

volumevolume Extranuclear, or electron, regionExtranuclear, or electron, region

– Most of the atomic volumeMost of the atomic volume– Almost none of the atom’s massAlmost none of the atom’s mass– Almost “empty space”Almost “empty space”

AtomAtom

Nucleus

Extra-nuclear (electron) region

Three Sub-atomic ParticlesThree Sub-atomic Particles

ElectronsElectrons– negative (-1)negative (-1)– negligible mass (0.0 negligible mass (0.0

amu)amu)– outside nucleusoutside nucleus

ProtonsProtons– positive (+1)positive (+1)– part of nucleuspart of nucleus– 1.0 amu1.0 amu

NeutronsNeutrons– neutralneutral– part of nucleuspart of nucleus– 1.0 amu1.0 amu

Atoms of Various ElementsAtoms of Various Elements

Same no. of pSame no. of p+ + for given elementfor given element– equal to atomic numberequal to atomic number– equal to e- no. for neutral atomsequal to e- no. for neutral atoms

Neutron nos. may vary for atoms Neutron nos. may vary for atoms of same elementof same element– isotopesisotopes– averageaverage no. of neutrons determinable no. of neutrons determinable

from atomic mass infofrom atomic mass info

1717

ClCl35.45335.453

No. of protonsNo. of protons

Average mass, Average mass, average total of paverage total of p++ & n & n

1717

ClCl35.45335.453

No. of protonsNo. of protons

Average no neutrons Average no neutrons 18.5 18.5

Two Isotopes for ClTwo Isotopes for Cl

17 p17 p++

18n18n17 p17 p++

20n20n

Mass = 35 amuMass = 35 amuca ca 75% of isotopes75% of isotopes

Mass = 37 amuMass = 37 amuca 25% of isotopesca 25% of isotopes

Average mass = 35.453Average mass = 35.453

Cl-35Cl-35 or or ClCl3535

1717Cl-37Cl-37 or or ClCl

3737

1717

1212

MgMg24.305024.3050

No. of protonsNo. of protons Average Average no no neutrons neutrons 12.3053 12.3053

Three Isotopes for MgThree Isotopes for Mg

12 p12 p++

12n12n12 p12 p++

13n13n

Mass = 24 amuMass = 24 amuca ca 79% of isotopes79% of isotopes


Average mass = 24.3050Average mass = 24.3050

Mg-24Mg-24 or or MgMg2424

1212Mg-25Mg-25 or or MgMg

2525

1212

12 p12 p++

14n14n


Mg-26Mg-26 or or MgMg2626

1212

Electron OrganizationElectron Organization

Outside nucleusOutside nucleus Grouped in increasing levels of Grouped in increasing levels of

energyenergy Lowest-energy eLowest-energy e-- nearest nucleus nearest nucleus Limited no. eLimited no. e-- at each level (more at at each level (more at

higher levels)higher levels) Transitions of eTransitions of e-- between levels between levels

absorb or release energyabsorb or release energy

Energy LevelsEnergy Levels

11

223344

5566 77 8, 9, 10, 8, 9, 10, etcetc

Levels Levels approach a approach a continuum for continuum for most atoms most atoms beyond then beyond then 10th level.10th level.

Electron TransitionsElectron Transitions

11

223344

5566 77 8, 9, 10, 8, 9, 10, etcetc

••

••Energy Energy absorbedabsorbed


11

223344

5566 77 8, 9, 10, 8, 9, 10, etcetc

••

••

Energy Energy releasedreleased


Give rise to absorption and Give rise to absorption and emission spectraemission spectra

Only certain colors (or Only certain colors (or wavelengths) observed for given wavelengths) observed for given elementelement

Spectrum (color set) for each Spectrum (color set) for each element can be used to identify element can be used to identify element in unknown sampleelement in unknown sample

SpectraSpectra

Maximum Occupancy of Maximum Occupancy of Energy LevelsEnergy Levels

Level 1 -- 2 eLevel 1 -- 2 e--

Level 2 -- 8 eLevel 2 -- 8 e--

Level 3 -- 18 eLevel 3 -- 18 e--

Level 4 -- 32 eLevel 4 -- 32 e--

…… Level Level nn -- 2 x -- 2 x n2 e-

Actual occupancy 32 e-

Energy LevelsEnergy Levels

11

223344

5566 77 8, 9, 10, 8, 9, 10, etcetc

Levels Levels approach a approach a continuum for continuum for most atoms most atoms beyond then beyond then 10th level.10th level.

2e2e--

8e8e--18e18e--

32e32e--

LithiumLithium

2e2e-- 1e1e--

33Li 2, 1Li 2, 1

Same as:Same as:

NitrogenNitrogen

2e2e-- 5e5e--

77N 2, 5N 2, 5

Same as:Same as:

NeonNeon

2e2e-- 8e8e--

1010Ne 2, 8Ne 2, 8

Same as:Same as:

Largest atom for which Largest atom for which all electrons exist only all electrons exist only at main levels 1 and 2.at main levels 1 and 2.

SodiumSodium

2e2e--

8e8e--

1111Na 2, 8, 1Na 2, 8, 1

Same as:Same as:

Smallest atom for which Smallest atom for which an electron must exist at an electron must exist at main level 3.main level 3.

1e1e--

ArgonArgon

2e2e--

8e8e--

1818Ar 2, 8, 8Ar 2, 8, 8

Same as:Same as:

Largest atom for which all Largest atom for which all electrons can exist within electrons can exist within first three main levels.first three main levels.

8e8e--

Atoms with At. No. > 18Atoms with At. No. > 18

2e2e--

8e8e--““Filling order”: Filling order”: Level 1 - 2eLevel 1 - 2e--

Level 2 - 8eLevel 2 - 8e--



Level 3 - up to 18 totalLevel 3 - up to 18 total

8e8e--

Although level Although level #3 can have 18 #3 can have 18 total electrons, total electrons, level #4 must level #4 must contain next contain next 22 electrons; electrons; additional additional electrons after electrons after the 20th go back the 20th go back to level #3 (up to to level #3 (up to 18, maximum).18, maximum).

PotassiumPotassium

2e2e--

8e8e--

1919K 2, 8, 8, 1K 2, 8, 8, 1

Same as:Same as:

Smallest atom for which Smallest atom for which energy level 4 must be energy level 4 must be occupied.occupied.

8e8e--

1e1e--

IronIron

2e2e--

8e8e--

2626Fe 2, 8, 14, 2Fe 2, 8, 14, 2

Same as:Same as:

Last 6eLast 6e--::

14e14e--

2e2e--

Filling:Filling:1st 18e1st 18e--: 2,8,8: 2,8,8Next 2eNext 2e--: 2,8,8,2: 2,8,8,2

2, 8, 14, 22, 8, 14, 2

ZincZinc

2e2e--

8e8e--

3030Zn 2, 8, 18, 2Zn 2, 8, 18, 2

Same as:Same as:

Last 10eLast 10e--::

18e18e--

2e2e--

Filling:Filling:1st 18e1st 18e--: 2,8,8: 2,8,8Next 2eNext 2e--: 2,8,8,2: 2,8,8,2

2, 8, 18, 22, 8, 18, 2

Good News!Good News!

Our requirements for electron Our requirements for electron configurations are -configurations are -– limited to 30 elimited to 30 e--, total (Zn), total (Zn)– involve main levels only (no involve main levels only (no s, p, d, fs, p, d, f

“orbital” or “subshell” configurations “orbital” or “subshell” configurations required)required)

Much of electron configuration Much of electron configuration determinable from Periodic Tabledeterminable from Periodic Table

Periodic Table of the ElementsPeriodic Table of the Elements

111122

111111

111100

101099

101088

101077

106106101055

101044

8989

AcAc8888

RaRa8787

FrFr

8686

RnRn8585

AtAt8484

PoPo8383

BiBi8282

PbPb8181

TlTl

8080

HgHg7979

AuAu7878

PtPt7777

IrIr7676

OsOs7575

ReRe7474

WW7373

TaTa7272

HfHf5757

LaLa5656

BaBa5555

CsCs

5454

XeXe5353

II5252

TeTe5151

SbSb5050

SnSn4949

InIn4848

CdCd4747

AgAg4646

PdPd4545

RhRh4444

RuRu4343

TcTc4242

MoMo

4141

NbNb4040

ZrZr3939

YY3838

SrSr

3737

RbRb

3636

KrKr3535

BrBr3434

SeSe3333

AsAs

3232

GeGe3131

GaGa3030

ZnZn2929

CuCu2828

NiNi

2727

CoCo2626

FeFe2525

MMnn2424

CrCr

2323

VV2222

TiTi2121

ScSc2020

CaCa

1919

KK

1818

ArAr1717

ClCl1616

SS1515

PP1414

SiSi1313

AlAl

1212

MMgg

1111

NaNa

1010

NeNe99

FF88

OO77

NN66

CC55

BB44

BeBe33

LiLi

22

HeHe11

HH

I

II III IV V VI VII

VIII

1

2

3

4

5

6

7

““Periodic” PropertiesPeriodic” Properties

Properties of the elements that Properties of the elements that change periodically (cyclically) as change periodically (cyclically) as the atomic number increases.the atomic number increases.

ExamplesExamples– Chemical reactivityChemical reactivity– Atomic size (diameter, radius, Atomic size (diameter, radius, eg.eg.))– Ionization energyIonization energy– ElectronegativityElectronegativity– Metallic/non-metallic characterMetallic/non-metallic character

Chemical ReactivityChemical Reactivity

Properties are similar for elements Properties are similar for elements in same in same familyfamily or vertical or vertical groupgroup..– Group I: Li, Na, K, Group I: Li, Na, K, etcetc– Group II: Be, Mg, Ca, Group II: Be, Mg, Ca, etcetc– Group VII: F, Cl, Br, I, Group VII: F, Cl, Br, I, etcetc

Similar kinds of reactionsSimilar kinds of reactions Similar kinds of compoundsSimilar kinds of compounds

Similar ReactionsSimilar Reactions

Consider Group I: Li, Na, K, Rb, CsConsider Group I: Li, Na, K, Rb, Cs

Li + HLi + H22O O explosive gas, alkaline solution explosive gas, alkaline solution

Na + HNa + H22O O explosive gas, alkaline solution explosive gas, alkaline solution

K + HK + H22O O explosive gas, alkaline solution explosive gas, alkaline solution

Rb + HRb + H22O O explosive gas, alkaline solution explosive gas, alkaline solution

Cs + HCs + H22O O explosive gas, alkaline solution explosive gas, alkaline solution

Requires warm Requires warm water; sluggishwater; sluggish

Vigorous in Vigorous in cool water; cool water; may explodemay explode

Explosion Explosion likely; very likely; very dangerousdangerous

Run! Call 911Run! Call 911

Our condolences.Our condolences.

Similar CompoundsSimilar Compounds

Again, consider Group I: Li, Na, K, Rb, CsAgain, consider Group I: Li, Na, K, Rb, Cs

““Sulfides”: LiSulfides”: Li22S, NaS, Na22S, KS, K22S, RbS, Rb22S, CsS, Cs22SS

““Chlorides”: LiCl, NaCl, KCl, RbCl, CsClChlorides”: LiCl, NaCl, KCl, RbCl, CsCl

““Phosphates”: LiPhosphates”: Li33POPO44,, NaNa33POPO44, K, K33POPO44, Rb, Rb33POPO44, , etcetc

Similar CompoundsSimilar Compounds

For Group II: Be, Mg, Ca, Sr, BaFor Group II: Be, Mg, Ca, Sr, Ba

““Sulfides”: BeS, MgS, CaS, SrS, BaSSulfides”: BeS, MgS, CaS, SrS, BaS

““Chlorides”: BeClChlorides”: BeCl22, MgCl, MgCl22, CaCl, CaCl22, SrCl, SrCl22, BaCl, BaCl22

““Phosphates”: BePhosphates”: Be33(PO(PO44))2, 2, MgMg33(PO(PO44))2, 2, CaCa33(PO(PO44))22, , etcetc

Atomic SizeAtomic Size

111122

111111

111100

101099

101088

101077

106106101055

101044

8989

AcAc8888

RaRa8787

FrFr

8686

RnRn8585

AtAt8484

PoPo8383

BiBi8282

PbPb8181

TlTl

8080

HgHg7979

AuAu7878

PtPt7777

IrIr7676

OsOs7575

ReRe7474

WW7373

TaTa7272

HfHf5757

LaLa5656

BaBa5555

CsCs

5454

XeXe5353

II5252

TeTe5151

SbSb5050

SnSn4949

InIn4848

CdCd4747

AgAg4646

PdPd4545

RhRh4444

RuRu4343

TcTc4242

MoMo

4141

NbNb4040

ZrZr3939

YY3838

SrSr

3737

RbRb

3636

KrKr3535

BrBr3434

SeSe3333

AsAs

3232

GeGe3131

GaGa3030

ZnZn2929

CuCu2828

NiNi

2727

CoCo2626

FeFe2525

MMnn2424

CrCr

2323

VV2222

TiTi2121

ScSc2020

CaCa

1919

KK

1818

ArAr1717

ClCl1616

SS1515

PP1414

SiSi1313

AlAl

1212

MMgg

1111

NaNa

1010

NeNe99

FF88

OO77

NN66

CC55

BB44

BeBe33

LiLi

22

HeHe11

HH

LARGE

small

2e2e--1e1e--

33Li 2, 1Li 2, 1 Same as:Same as:

1111Na 2, 8, 1Na 2, 8, 1 Same as:Same as:2e2e--

8e8e--1e1e--

1919K 2, 8, 8,1K 2, 8, 8,1 Same as:Same as:2e2e--

8e8e--8e8e--1e1e--

Atomic DiameterAtomic Diameter

Increases Increases going going down a down a “family” “family” or or groupgroup..

More More energy energy levels levels occupied.occupied.



2e2e--

1e1e--

33++

66C 2, 4C 2, 4 Same as:Same as:

2e2e--

4e4e--

66++2e2e--

7e7e--

99++

99F 2, 7F 2, 7

Same as:Same as:

Diameter shrinks going rightward across a Diameter shrinks going rightward across a periodperiod..


1111Na 2, 8, 1Na 2, 8, 1 Same as:Same as:

1919K 2, 8, 8,1K 2, 8, 8,1 Same as:Same as:


2e2e--1e1e--3+3+

2e2e--

8e8e--1e1e--11+11+

2e2e--

8e8e--

8e8e--

1e1e--19+19+

Approx +1 at outer levelApprox +1 at outer level



““Shielding Shielding by “core” by “core” electrons electrons keeps keeps effective effective charge at charge at outer level outer level about the about the same same within a within a family or family or group. group.

Ionization Energy Ionization Energy (Potential)(Potential)

Minimum energy required to remove Minimum energy required to remove electron from gaseous atom:electron from gaseous atom:X(X(gg) + I.E. ) + I.E. e e- - + X+ X++((gg))

I.E. is high for atoms which hold very I.E. is high for atoms which hold very tightly to their outer electronstightly to their outer electrons– non-metals have high I.E.’s; metals, lownon-metals have high I.E.’s; metals, low– highest for smallest atoms.highest for smallest atoms.

IonIon -- at atom -- at atom (or group of (or group of atoms) with atoms) with net chargenet charge

LARGE SIZE

Ionization EnergyIonization EnergySmall size

111122

111111

111100

101099

101088

101077

106106101055

101044

8989

AcAc8888

RaRa8787

FrFr

8686

RnRn8585

AtAt8484

PoPo8383

BiBi8282

PbPb8181

TlTl

8080

HgHg7979

AuAu7878

PtPt7777

IrIr7676

OsOs7575

ReRe7474

WW7373

TaTa7272

HfHf5757

LaLa5656

BaBa5555

CsCs

5454

XeXe5353

II5252

TeTe5151

SbSb5050

SnSn4949

InIn4848

CdCd4747

AgAg4646

PdPd4545

RhRh4444

RuRu4343

TcTc4242

MoMo

4141

NbNb4040

ZrZr3939

YY3838

SrSr

3737

RbRb

3636

KrKr3535

BrBr3434

SeSe3333

AsAs

3232

GeGe3131

GaGa3030

ZnZn2929

CuCu2828

NiNi

2727

CoCo2626

FeFe2525

MMnn2424

CrCr

2323

VV2222

TiTi2121

ScSc2020

CaCa

1919

KK

1818

ArAr1717

ClCl1616

SS1515

PP1414

SiSi1313

AlAl

1212

MMgg

1111

NaNa

1010

NeNe99

FF88

OO77

NN66

CC55

BB44

BeBe33

LiLi

22

HeHe11

HH LARGE I.E.

small I.E.

ElectronegativityElectronegativity

Tendency of atom to hold to its Tendency of atom to hold to its electron when electron when sharingsharing electrons electrons with neighboring atom.with neighboring atom.

Generally, follow same trends as Generally, follow same trends as I.E.I.E.

Important for bonding polarity Important for bonding polarity (next unit of study)(next unit of study)

Metallic CharacterMetallic Character

112111110109Mt

108Hs

107Bh

106Sg

105Db

104Rf

89Ac

88Ra

87Fr

8686

RnRn85At

84Po

83Bi

82Pb

81Tl

80Hg

79Au

78Pt

77Ir

76Os

75Re

74W

73Ta

72Hf

57La

56Ba

55Cs

5454

XeXe5353

II52Te

51Sb

50Sn

49In

48Cd

47Ag

46Pd

45Rh

44Ru

43Tc

42Mo

41Nb

40Zr

39Y

38Sr

37Rb

3636

KrKr3535

BrBr3434

SeSe33As

32Ge

31Ga

30Zn

29Cu

28Ni

27Co

26Fe

25Mn

24Cr

23V

22Ti

21Sc

20Ca

19K

1818

ArAr1717

ClCl1616

SS1515

PP14Si

13Al

12Mg

11Na

1010

NeNe99

FF88

OO77

NN66

CC5B

4Be

3Li

22

HeHe11

HH

Metals

Non-

metals

atomic structure nuclear and electronic organization

Documents

elevel n

eenergy levels12345678

esmallest atom

elargest atom

efilling order

higher levelstransitions

n2 eactual occupancy

atomic mass info17cl35