Particle Theory of Matter (Kinetic Theory of Matter) All matter is made of tiny particles called ATOMS. Atoms are always moving (they have kinetic energy). The faster the particles move higher the temperature of matter. A state of matter is the form in which matter exists: solid, liquid, gas. The differences between solids, liquids & gases can be explained with this theory.

States of Matter There are 3 states of matter: Solid Liquid & Gas

States of Matter

Solids Liquids Gases Can’t be compressed into a smaller volume Have a fixed volume Can’t be compressed into a smaller volume Keeps it shape even when moved Very dense Solids Have a fixed volume Can’t be compressed into a smaller volume Takes the shape of its container Flows easily Dense Liquids Does not have a fixed volume Can be compressed into a smaller volume Will fill all available space Flows easily Not dense Gases

Solid Liquid Gas

Solids Liquids Gases Particles are vibrating Particles can not move around each other Particles held together by strong forces of attraction Particles are close together Solids Particles are free to move past each other Particles held together by forces of attraction Particles still close together Liquids Particles are moving very fast Particles are far apart Almost no forces of attraction between particles Gases

Energy & Changes of States of Matter Changes of state of matter in a system are caused by changes in thermal energy in the form of heat. Thermal energy can be added to a system (absorbed) or given off (released). As a result of adding or releasing thermal energy, particles of some substances may gain or lose enough energy to change state. When energy is absorbed the process is called endothermic. When energy is released the process is called exothermic. CHANGES MELTING EVAPORATING BOILING FREEZING CONDENSATION SUBLIMATION DEPOSITION PHYSICAL CHANGE SOLID TO LIQUID LIQUID TO GAS LIQUID TO SOLID GAS TO LIQUID SOLID TO GAS VAPOR (GAS) TO SOLID ENERGY CHANGE ENERGY ABSORBED ENERGY RELEASED