1. States of Matter
Phase Changes

3. Solids
Definite volume and definite shape
Particles are tightly packed in fixed positions
Vibrate back and forth
Crystalline solids – particles have a regular, repeating pattern; have
a specific melting point; sugar, salt
Amorphous solids – particles are randomly arranged; no specific
melting point, become softer; plastic, glass, butter
Has the lowest energy level of the three states

4. Liquids
Have definite volume but not definite shape
Particles are closely packed but move freely around each other
Fluid – they flow
Surface tension – particles pull in ward and form a “skin”
Viscosity – the resistance to flow
high viscosity = honey, molasses, syrup
low viscosity = water, vinegar, koolaid
Has the middle level of energy of the three states

5. Gases
Do not have definite volume or definite shape
Particles spread out to fill any space, changing shape and volume
fluid
Has the highest energy level of the three states

6. Melting
Solids
Liquids
Particles speed up
Gain energy
Endothermic change
Freezing
Particles slow down
Lose energy
Exothermic change

7. Liquids
Condensation
Particles slow down
Lose energy
Exothermic change
Vaporization
Boiling – occurs throughout
the liquid
Gas
Particles speed up
Gain energy
Evaporation – occurs of the
Surface of the liquid
Endothermic change

8. Solids
Deposition
Particles slow down
Lose energy
Sublimation
Exothermic change
Particles speed up
Gain energy
Gas
Endothermic change