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, sp², sp³ sp³d, sp³d², 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