Now We Can Understand
• Arrangement of the Periodic Table of Elements• Trends in Atomic Size• Trends in Ionization Energy• Trends in Electron Affinity• Trends in Electronegativity• Various Types of Chemical Bonds• Combining Ratios of Oxides and Hydrides• Shapes of Molecules
Invented the periodic table in 1869. Also in that year, he published his book, "Principles of Chemistry." His book compared the atomic
weights and the properties of elements that were not known back then.
1906: One vote away from winning a Nobel PrizeDied in 1907
Dmitri Mendeleev
St. Petersburg University
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
Solid-State Molar Volumes ( )3D3D
Molar volume
( )cm3
mol
Cs
Ba
HHe
RnSrY
Lu
Sc Ti V CrZrHf Ta W
Nb MoRe Os Ir Pt Au Hg Tl Pb Bi Po
RbK
Ca
NaMg
Al Si P S Cl ArLi
Be
Tc Ru Rh Pd Ag Cd In Sn Sb Te IXe
Mn Fe Co Zn GaNi Cu Ge As Se BrKr
BONC F Ne
At
In 1875, Lothar Meyer deduces a periodic trend
* E(eV)0
-13.616
-13.69
-13.64
-13.61
(vacuum energy)
1s
2s 2p
3s 3p
4s 4p 4f4d
3d
Energy of One Electron in a H atom
* E = -kn2
where k=13.6 eV;n is the principal quantum number
On Average, Zeff < ZHow Much Less Zeff < Z Determines Atomic Properties
Multiple-Electron Atoms
None of the e- eclipsed: Zeff = Z
One e- eclipsed: Zeff = Z - 1
An electron in the 2p orbital penetratessomewhat into the 1s orbital
Shieldingr2R2
r2R2 = probability offinding an electronon the sphere of radius r
1s2p 2s
r
Shielding
But a 2s electron penetrates the 1sorbital better than a 2p electron
r2R2
r2R2 = probability offinding an electronon the sphere of radius r
1s2p 2s
r
Shielding
A 3s electron penetrates the 1sorbital better than a 3p electron
r2R2
r
1s 3d 3p3s
Penetration:3s > 3p > 3d
Shielding
A 4s electron penetrates the 1sorbital better than a 4p electron
r2R2
rPenetration:4s > 4p > 4d > 4f
1s 4f 4d4s
4p
Another View of 2s vs 2p Shielding
1s
2pshielded electron density
1s2s
2s Penetrates More into 1s Than Does 2p2s is Therefore Lower in E Than 2p
1s
2s 2p
3s3p
5s
4p 3d
Energy of Multi-Electron Atoms
4s
E
(e t c.)0
due to shielding, orbitalswith the same principalquantum number(n) do NOThave the same energies
1s
2s
3s
4s
5s
2p
3p
4p
5p
3d
4d
5d
4f
5f
Mnemonic for Filling Order
hence the filling order is:1s, 2s, 2p, 3s,3p, 4s, 3d, etc.
1s
2s2p
3s3p
5s
4p3d4s
E 1. H (1s)1
2. He (1s)2
3. Li (1s)2(2s)1
4. Be (1s)2(2s)2
e t c.0
5. B (1s)2(2s)2(2p)1
6. C (1s)2(2s)2(2p)2
7. N (1s)2(2s)2(2p)3
8. O (1s)2(2s)2(2p)4
9. F (1s)2(2s)2(2p)5
10. Ne (1s)2(2s)2(2p)6
elementshellelectrons in shellvalence electrons
(underlined)
2p- orbital
e t c.
Valence Electrons
Valence Electrons:electrons in the outermost shell (in other words, the setof electrons with highestprincipal quantum number)
↑ ↑ ↑↑ ↑ ↑↑↓ ↑ ↑↑↓ ↑↓ ↑↑↓ ↑↓ ↑↓
Orbital Filling EnergiesExample:
lowest energy for 3 electrons in p orbital
↑ ↑ ↑
↑↓ ↑
↑ ↑ ↓
energy increases when a second electron is putin same orbital
energy also increases when spins are mixed in orbitals
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Exceptions to Filling Order
23. V (4s)2(3d)3
24. Cr (4s)1(3d)5
25. Mn (4s)2(3d)5
40. Zr (5s)2(4d)2
41. Nb (5s)1(4d)4
42. Mo (5s)1(4d)5
Exceptions occur because electrons don’t like to pair up in orbitals; so the highlighted atoms have lower energy.
↑
↑↓ 4s 3d
2s 2p3s
4s 3d3p
4p
↑ ↑ ↑ ↑ ↑
↑ ↑ ↑ ↑ ↑
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Element GroupsAlkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Hydrogen:From Greek: Hydro-genes: “Water forming”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Iodine: violet crystalsFrom Greek “iodes”: “violet”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
CarbonFrom Latin“carbo”: “charcoal”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
CalciumFrom Latin“calx”: “limestone”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Iron: FeFrom Latin“iron”: “ferrum”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Gold: AuFrom Latin“aurum”: “shining dawn”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScYLaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rI
A t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Lead: PbFrom Latin“plumbum”: “heavy”
HLiNaKRbCsFr
BeMgCaS rB aRa
ScY
LaAc
T iZ rHf
VNbTa
C rMoW
M nTcRe
FeR uO s
CoR hI r
N iPdP t
CuA gA u
ZnCdH g
BA lGaI nT l
CS iGeSnPb
NPAsSbB i
OSSeTePo
FC lB rIA t
HeNeA rKrXeRn
C e Pr Nd Pm Sm E u Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm B k C f E s Fm Md No Lr
Alkali metals
Transition metals
Alkali earths Halogens
Inert or Noble gases
LanthanidesActinides
Cobalt: CoFrom German“kobold”: “goblin or evil spirits”
Unwanted metal in what were thought to be copper ores
Effective Nuclear Charge
e-
p
e-
p
e-
H H-
e- p
H
p
He
p
(Zeff = 1.0)
(Zeff ≈ 0.7)
(Zeff = 1.0)
(Zeff ≈ 1.8)
e- e-
e-
e-H H-
H He
(Zeff = 1.0)
(Zeff ≈ 0.7)
(Zeff = 1.0)
(Zef f ≈ 1.8)
Atomic Size and Ionization Energy
Bigger
Smaller
e-
p p
e-p
e- ppe-
Trends in Zeffe-
p
H (Zeff =1.0)
1s
e-
Be (Zeff ≈2.0 in n=2)
pe-
p p e-
1sp Smaller
Again
e-
2s
e- p
He
pe-
(Zeff ≈1.8)
Smaller1s
pp p
1s
2s
e-
e- e-
Li (Zeff ≈1.2 in n=2)
Bigger
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Atomic Sizes
LiBe
Na
Z=11
Zeff ≈1.0 (n=3)
Z=3
Zeff ≈1.2 (n=2) Zeff ≈2.0 (n=2)
Bigger
Bigger
Z=4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180
20
40
60
80
Solid-State Molar Volumes ( )3D3D
Molar volume
( )cm3
mol
Cs
Ba
HHe
RnSrY
Lu
Sc Ti V CrZrHf Ta W
Nb MoRe Os Ir Pt Au Hg Tl Pb Bi Po
RbK
Ca
NaMg
Al Si P S Cl ArLi
Be
Tc Ru Rh Pd Ag Cd In Sn Sb Te IXe
Mn Fe Co Zn GaNi Cu Ge As Se BrKr
BONC F Ne
At
Atomic Radius: A Closer LookH
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
(relative atomic sizes)(expected size)
HeH Li Be B C
↑
↑↓
1s: ↑↓
↑↓
↑↓
↑↓
2s: ↑
↑
↑↓
↑↓
↑↓
↑
↑
2p:
Closed 2s shell;r Smaller than expected
2p more fully screened than 2sr Bigger than Expected
Exceptions to Atomic Radius TrendSc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
B C N O F Ne
(relative atomic sizes) (expected sizes)
1s:2s:2p:
↑↓
↑
↑↓
↑↓
↑↓
↑↓
↑
↑↓
↑↓
↑↓
↑↓
↑
↑↓
↑↓
↑↓
↑ ↑ ↑ ↑ ↑ ↑ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓
Half-filled p Shellr Smaller Than Expected
Extra Repulsion in 2p setr Bigger Than Expected
Ionization Energies
Larger
Smaller Atoms Harder to Remove Electrons
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnHf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm B k Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Cs La
Ac
Cs
Sc
Y
Larger
e-
p
H
e- p
He
p
e-
(Zeff =1.0) (Zeff ≈1.8)
Smaller rHigher I.E.
1s 1s
0
EH
He
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 170
500
1000
1500
2000
2500
First Ionization Energy ( )3D3D
1st IE
( )kJmol
Details of Ionization Energies
Smaller r = Higher I.E.
H
He
Li
Be
B
C
N
O
F
Ne2p vs 2s shielding
2p pairing penalty
Ionization Energy (kJ/mol)
500
1000
1500
2000
2500
Atomic Number0 1 2 3 4 5 6 7 8 9 10 11
Radius decreases for isoelectronic atoms asPositive charge increases ( )
Discontinuity at K+ due to d-orbitals (increased Zeff)
0
0.5
1
1.5
2
2.5
3
0 20 40 60 80
Atomic Number
Ionic Radii
Li+
Na+K+
Rb+Cs+
Be2+Al3+
Ti4+ Zr4+ Hf4+
N3-
P3- As3-Sb3-
Ionic
Radius
Å
Lanthanide Contraction
Responsible for many features of TM’s that followLanthanides in periodic table
0
0.2
0.4
0.6
0.8
1
1.2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Series1
Ionic
Radius
Å
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu (M3+)
All are 5s25p64fn-1
Electron Affinity
Energy Released By Addition of an Electron to the Element
e-
p
e-
p
e-
H
+ e-
H-
E.A.of H
By Definition, E.A is Positive when Energy is Released(Opposite the thermodynamic definition!)
E = –77 kJ/mol E.A. = 77 kJ/mol
Electron Affinity vs. Ionization Energy
E.A.of H
I.E. of H-
(+) Electron Affinity of Element X (+) Ionization Energy of Anion X-
=
e-
p
H
+ e- p
e-
H-
e-
Electron Affinity
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnHf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm B k Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Cs La
Ac
Cs
Sc
Y
He
Ne
Ar
Kr
Xe
RnRn
Larger
Larger
O
F
Ne
+
+
+
EA
142
kJ/mol
333
-29
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Electron Affinity ( )3D3D
E.A.
( )kJmol
Note: Black elements have negative EA’s
Electron Affinity vs.Ionization Energy
Electron Affinity• Can be either + or - in sign• No atom has a positive 2nd E.A.
Ionization Energy• Always Positive• 2nd I.E.s are always > 1st I.E.’s
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm B k Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Cs La
Ac
Cs
Sc
Y
Electronegativity
Electronegativity Generally Follows I.E. Trend
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnHf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
EN = I.E. + E.A.
2
Larger
Larger
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180
0.51
1.5
2
2.5
3
3.5
4
Electronegativity ( )3D3D
(ArbitraryPauling units)
Electronegativity, I.E., and E.A.
• In a bond, the distribution of electrons is determined by how much each atom pulls on its own as well as the other atom’s electrons. So electronegativity = I.E. + E.A.
Table Salt• Na has low E.A. and I.E.• Cl has high E.A. and I.E.• Electronegativity = (I.E. + E.A.)/2
Cl is more electronegative than Na.
Example:
Na Cl
e- - - -- --
+
++
++
+
EN ENsmall big
Some Representative Electronegativities
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
RnHf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnCe Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm B k Cf Es Fm Md No Lr
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Cs La
Ac
Cs
Sc
Y
Electronegativities:
Be = 1.6 C = 2.6
F = 4.0
Na = 0.9 As = 2.2
Fr = 0.7
• Fluorine has the highestelectronegativity, Francium has the lowest E.N.
Larger
Larger
Types of Chemical Bonds
Ionic Bonding
Na• + Cl• [Na]+ [ Cl]-
Na has Low I.E., low E.A. Lower EN; loses e-
Cl has High I.E., high E.A. Higher EN; gains e-
Li• + H• [Li]+ [ H]-
Li has Low I.E., low E.A. Lower EN; loses e-
H has High I.E., high E.A. Higher EN; gains e-
Types of Chemical Bonds
Covalent BondingCl + Cl Cl Cl = Cl—ClH + Br H Br = H—BrElectrons Shared ≈ Equally
Hydrogen Bonding: Cl—H...OH2
Van der Waals Bonding: Ar...HCl
Now We Can Understand
• Arrangement of the Periodic Table of Elements• Trends in Atomic Size• Trends in Ionization Energy• Trends in Electron Affinity• Trends in Electronegativity• Various Types of Chemical Bonds• Combining Ratios of Oxides and Hydrides• Shapes of Molecules
Periodic Trends in Bonding
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Stoichiometry of Binary Hydrides
LiH BeH2
NaH MgH2
BH3 CH4 NH3 H2O HFAlH3 SiH4 PH3 H2S HCl
H- H+
Periodic Trends in Bonding
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Stoichiometry of Binary Oxides
HaXb for Hydrides; Oa/2Xb (Usually) for Oxides
Li2O BeONa2O MgO
B2O3 CO2 N2O5 O2 OF2
Al2O3 SiO2 P2O5 SO3 OCl2
Al normally inert due to formation of tough surface coating of Al2O3Al metal burns in air and if hot enough, will form Al2O3 continuously from H2O
H.M.S. SheffieldFalklands War of 1982
Na2O(s) + H2O 2 Na+(aq) + 2 OH-(aq)BaO(s) + H2O Ba2+(aq) + 2 OH-(aq)
MnO(s) + 2H+ Mn2+(aq) + H2ONiO(s) + 2H+ Ni2+(aq) + H2O
SO3(s) + H2O H+(aq) + HSO4-(aq)
P4O10(s) + 6H2O 4 H+(aq) + 4H2 �O PO3-(aq)
• Basic oxides have pushed too much electron densityOnto O, and it loses it by reacting with H2O (liberating OH-)• Acidic oxides have less electron density than theycan accomodate, and so grab more O from H2O (liberating H+)
Basic
Basic
Acidic
Acid/Base Properties of Oxides
H
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
Hf
V
Nb
Ta
Cr
Mo
W
Mn
Tc
Re
Fe
Ru
Os
Co
Rh
Ir
Ni
Pd
Pt
Cu
Ag
Au
Zn
Cd
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
O
S
Se
Te
Po
F
Cl
Br
I
At
He
Ne
Ar
Kr
Xe
Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Acidity increases going up and to right
Li2O BeONa2O MgO
B2O3 CO2 N2O5 O2 OF2
Al2O3 SiO2 P2O5 SO3 OCl2
Basic
Acid/Base Properties of Oxides