Ch.10

Intermolecular Forces (IMFs)

Attractions between molecules.

Dispersion Forces (London Forces)

Present in all molecules, caused by temporary dipoles from electron movement.

Dipole-Dipole Interactions

Attractions between polar molecules, stronger than dispersion forces.

Hydrogen Bonding

Strongest type of IMF, occurs when H is bonded to N, O, or F.

Viscosity

Resistance to flow of a liquid.

Surface Tension

Energy required to increase the surface area of a liquid.

Capillary Action

Liquid rises or falls in a narrow tube due to adhesive and cohesive forces.

Boiling Point

The temperature at which vapor pressure equals atmospheric pressure.

Melting Point

Temperature at which solid and liquid are in equilibrium.

Sublimation

The phase transition from solid to gas.

Deposition

The phase transition from gas to solid.

Vapor Pressure

Pressure exerted by vapor in equilibrium with its liquid.

Triple Point

Point where solid, liquid, and gas phases are in equilibrium.

Critical Point

Point beyond which liquid and gas phases are indistinguishable.

Simple Cubic (SC)

Unit cell structure with 1 atom/cell, coordination number 6, 52% packing efficiency.

Body-Centered Cubic (BCC)

Unit cell structure with 2 atoms/cell, coordination number 8, 68% packing efficiency.

Face-Centered Cubic (FCC/CCP)

Unit cell structure with 4 atoms/cell, coordination number 12, 74% packing efficiency.

Hexagonal Closest Packing (HCP)

Unit cell structure with coordination number 12, 74% packing efficiency.

Packing Efficiency

Comparison of how tightly unit cells are packed together in a crystalline structure.