unit 4

Ionic Compounds

Formed when oppositely charged ions attract.

Ionization

The process where electrons are transferred between atoms.

Ionic Bonds

Electrostatic forces that hold oppositely charged ions together.

Lattice Structure

A predictable 3D crystalline structure of ionic compounds.

Coordination Number

The number of ions surrounding a given ion in the lattice.

Lattice Energy

A measure of the strength of attraction between the ions in the lattice.

Volatility

The tendency of a substance to vaporize; ionic compounds have low volatility.

Hydration

The process where ions are surrounded by water molecules.

Solvation

Occurs when ionic compounds are dissolved in something other than water.

Covalent Bonds

Form by atoms sharing electrons, typically between non-metals.

Octet Rule

Atoms tend to achieve an outer shell with eight electrons when they react.

Bond Length

A measure of the distance between two bonded nuclei.

Bond Strength

Described in terms of bond enthalpy, measuring energy required to break the bond.

Polar Bonds

Result from unequal sharing of electrons due to electronegativity differences.

Dipole

A separation of charges resulting from polar bonds.

VSEPR Theory

Valence Shell Electron Pair Repulsion Theory used to predict 3D shapes of molecules.

Intermolecular Forces

Forces that exist between molecules, determining physical properties.

London Forces

Weak attractions between temporary dipoles of molecules.

Dipole-Dipole Attraction

Attraction between opposing charges of polar molecules.

Hydrogen Bonding

A strong intermolecular force between hydrogen and highly electronegative atoms like F, O, or N.

Solubility

The ability of a substance to dissolve in a solvent.

Electrical Conductivity

Covalent compounds do not conduct electricity unless they can ionize.