1. Physical Properties of Matter Mass: The amount of atoms in a substance Weight: The mass relative to gravity Volume: The area an object occupies Density: The mass of substance in a given area

2. Physical Properties Those Properties which are observed without changing the identity of the substance Such as same substances (H 2 O) in different states or phases. Liquid water Water vapor Ice

3. Matter can exist in 4 phases: 1.Solid – crystal – repeating structure amorphous – lose shape in certain conditions (like wax) 2.Liquid – no definite shape, takes the shape of the container 3.Gas – no definite shape, fills available space, regardless of size or shape 4.Plasma – stars, and some high energy experiments on earth

4. Phase Changes Heat energy causes the particles to move faster & further apart gas > liquid > solid decreasing energy Add or take away energy to change phase

5. Physical Changes Melting (s l) Freezing (l s) Vaporization (l g) Condensation (g l) Sublimation (s g) Physical properties get altered, but the substance is the same

7. A – Ice receives heat particles – vibrate faster B – No rise in temp, but heat energy is increasing – melting C – Temp rises – particles gain energy and move faster D – No rise in temp, but heat energy is increasing – boiling E – continued heating – particles vibrate faster

8. Why the Horizontal Line? There is an increase in heat energy, but not in temperature. The heat energy that is absorbed is used to overcome forces that hold the particles of substance together. Once the forces have been overcome and the substance has changed phase, added energy causes a rise in temperature.