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Review
Inorganic Chemistry
Chemistry 20
More than 20 million compounds are composed of these 116 elements.
Element: is a substance consists of identical atoms.
Cannot be divided by chemical & physical methods.
Carbon, Hydrogen, Oxygen
116 elements – 88 in nature
main-group elements: 1A to 8A
transition elements: 1B to 8B (3 – 12)
inner transition elements: between B3 & B4 (58 to 71 and 90 to 103)
Column: same properties (main group)
row or period
nonmetals
metals
metalloids
Classification of the elements
metals: solid (except mercury), shiny, conductors of electricity, ductile, malleable
nonmetals: solid, liquid or gas, do not conduct electricity (except graphite)
metalloids: between metals and nonmetals
to
n=1
n=2n=3 n=4
n=5
E1 E2 E3 E4 E5
Bohr model
Principal energy levels or Shell
324
183
82
21
Maximum number of electrons
Level
Lower energy
Higher energy
Sublevel: s p d f
Orbital: is a region of space and it can hold 2 electrons (max).
s p d f
2 2+2+2=6 2+2+2+2+2=10 2+2+2+2+2+2+2=14
Level OrbitalsMaximum number
of electrons
1 1s 2
2 2s, 2p 2 + 6 = 8
3 3s, 3p, 3d 2 + 6 + 10 = 18
4 4s, 4p, 4d, 4f 2 + 6 + 10 +14 = 32
3
2
3d3p
3s2p
2s
Principal energy level Orbitals
En
erg
y
Ord
er
of
filli
ng
1 1s
Orbital box diagrams
H (1)1s
1s1
Electron configuration
1sHe (2) 1s2
Li (3)
1s 2s
1s2 2s1
C (6)
1s 2s
1s2 2s2 2p2
2px 2py 2pz
Electrons configuration: description of the orbitals that its electrons occupy.
Valence electrons: outer-level electrons
Valence level: outer level
Cl (17) 1s2 2s2 2p6 3s2 3p5 7 valence electrons
Ar (18) 1s2 2s2 2p6 3s2 3p6 8 valence electrons
C (6) 1s2 2s2 2p2 4 valence electrons
Ne (10) 1s2 2s2 2p6 8 valence electrons
Noble gases Filled valence levels
Lewis dot structure
H He Li C Cl
1A 2A 3A 4A 5A 6A 7A 8A
Level 1
main-group elements
1A – 8A
Maximum 2 electrons in valence level
Hydrogen and Helium
Other Levels Maximum 8 electrons in valence level
1. Ionic bonds
2. Covalent bonds
Chemical Bonds
Goal of atoms Filled valence levelNoble gases
(Stable)
Na+: 1s2 2s2 2p6
+ e-
Na: 1s2 2s2 2p6 3s1 Ne: 1s2 2s2 2p6
Ar: 1s2 2s2 2p6 3s2 3p6
Octet rule
Octet rule
Goal of atoms Filled valence level
+ e-
Ar: 1s2 2s2 2p6 3s2 3p6
Noble gases (Stable)
Cl: 1s2 2s2 2p6 3s2 3p5 Cl-: 1s2 2s2 2p6 3s2 3p6
Na+: 1s2 2s2 2p6
+ e-
Na: 1s2 2s2 2p6 3s1 Ne: 1s2 2s2 2p6
Ionic bonds
Metal-Nonmetal
Na: 1s2 2s2 2p6 3s1 Cl: 1s2 2s2 2p6 3s2 3p5
AnionCation
Na+: 1s2 2s2 2p6 Cl-: 1s2 2s2 2p6 3s2 3p6
Covalent bonds
Nonmetal-NonmetalMetalloid-Nonmetal
Sharing ofvalence electrons
Lewis Dot Structure
H He Li CAl N Cl
H H Or H H
Or Cl H
Lewis Structure
HCl
Cl: 1s2 2s2 2p6 3s2 3p5
H: 1s1 He: 1s2
Ar: 1s2 2s2 2p6 3s2 3p6
Covalent compounds
H – C – H
–OCH2O H C H
OH – C – H
–O
H C H
O –
Correct
H C HH
HH – C – H
–H
–
H
CH4
H – N – H
–HNH3 H N H
H
H C C H
C – C
C2H4
H H
HH
H
H
H C C H
C = C
H H
HH
H
H
H C C H
H – C – C – H
C2H2H C C H
H – C C – H
Correct
Electronegativity
A measure of an atom’s attraction for the electrons
Covalent bonds
Nonpolar covalent bond: electrons are shared equally.
Polar covalent bond: electrons are shared unequally.
H Clδ+ δ-
Dipole
Polarity
1. Molecule has polar bonds.2. Its centers of δ+ and δ- lie at different places (sides).
O = C = O
δ- δ+ δ-
nonpolar molecule
H – C – H–H
–
H
δ+
δ+
δ+
δ+
δ-
C
=O
H Hδ+
δ-
polar molecule
N
HH H
δ-
δ+
Intermolecular Forces
London dispersion forces
Dipole-dipole interaction
Hydrogen bonding
Ionic bondsCovalent bonds<
Intramolecular (Bonding) Forces
Intermolecular Forces
London dispersion forces
Attractive forces between all molecules
Only forces between nonpolar covalent molecules
2+
No PolarityOriginal Temporary
Dipole
δ- δ+
+2+
HeHe
Original Temporary Dipole
Induced Temporary Dipole
__ _ _
He He
2+_ ___ 2+
δ- δ+He
__ 2+
δ- δ+He
__ 2+
Dipole-Dipole Interactions
Attractive force between two polar molecules
stronger than London dispersion forces
boiling point ↑
Hydrogen Bonds
stronger than Dipole-Dipole and London dispersion forces
surface tensionHigh boiling point
H2O
Between H bonded to O, N, or F (high electronegativity) → δ+and a nearby O, N, or F → δ-
Hydrogen bonding
CH3COOH
Acetic acidδ-
δ+
Factors that affect boiling point:
1. Intermolecular forces:
London dispersion forces < Dipole-Dipole interactions < Hydrogen bonds
3. Molecular shape: With the same molecular weight.
linear CH3-CH2-CH2-CH2-CH3 > spherical CH3-C- CH3
_
_
CH3
CH3
2. Number of sites for intermolecular interaction (surface area):
Larger surface areas (more electrons) more sites for L.D.F b.p.
CH3-CH2-CH2-CH2-CH3 > CH3-CH2-CH3
Boiling point