AP Chemistry Unit 2

Ionic Bonds

when one atom takes an electron from another (metal + nonmetal)

Covalent Bonds

the equal (or unequal) sharing of electrons between atoms (nonmetal + nonmetal)

Metallic Bonds

when neither atoms have a strong attraction to an electron (metal + metal)

Metallic Substances

held by metallic bonds, good conductors of electricity/heat, don’t dissolve, malleable/ductile

Molecular Compounds

do not conduct electricity, some of them dissolve

Ionic Solids

held by ionic bonds, very high melting/boiling point, don’t conduct electricity as solids but do when dissolved/melted

Covalent-Network Solids

held by covalent bonds, high melting/boiling points, don’t dissolve, don’t conduct electricity

Lattice Energy

energy required to separate one mole of ionic compounds

Larger Atomic Radius

decreases lattice energy

Bond Order

number of bonds between a pair of atoms

Higher Bond Order

shorter bond length due to higher electrostatic attraction

Formal Charge Formula

valence electrons - # of bonds - # each electron around atom

Alloys

a mixture of one or more elements with metallic properties

Substitutional Alloy

formed by elements with a similar atomic radii

Interstitual Alloy

formed by elements w/different atomic radii

2 Domain, 0 LP

linear

3 Domain, 0 LP

trigonal planar (120)

4 Domain, 0 LP

tetrahydral (109.5)

5 Domain, 0 LP

trigonal bipyramidal (120/90)

6 Domain, 0 LP

octahedral (90)

Sigma Bonds

formed by head-to-head overlap of orbitals (stronger)

Pi Bonds

formed by side-by-side overlap of orbitals (weaker)

Hybrid Orbitals Order

sp, sp^2, sp^3 sp^3d, sp^3d^2, etc

Dipole Atoms

atoms with equal but opposite charges

Nonpolar Covalent Electronegativity Difference

0.0-0.04

Polar Covalent Electronegativity Difference

0.4-2.1

Ionic Electronegativity Difference

>1.7

3 Domain, 1 LP

bent

4 Domain, 1 LP

trigonal pyramidal

4 Domain, 2 LP

bent

5 Domain, 1 LP

seesaw

5 Domain, 2 LP

t-shaped

5 Domain, 3 LP

linear

6 Domain, 1 LP

square pyramidal

6 Domain, 2 LP

square planar

6 Domain, 3 LP

t-shaped

6 Domain, 4 LP

linear