Major Understanding
The three phases of matter (solids, liquids, and gases) have different properties.
Heat is a transfer of energy (usually thermal energy) from a body of higher temperature to a body of lower temperature. Thermal energy is associated with the random motion of atoms and molecules.
Skills
Use a simple particle model to differentiate properties of a solid, a liquid, and a gas.
Qualitatively interpret heating and cooling curves in terms of changes in kinetic and potential energy, heat of vaporization, heat of fusion, and phase changes.