​Matter & Kinetic Energy

​The Kinetic Theory of Matter states that the particles that make up matter are always in motion and have kinetic energy. At different states, the particles have different amounts of average kinetic energy. As particles lose or gain energy, they can change into different states.

​Solids

• Solid substances have a definite shape and volume

• Particles cannot move, only vibrate​

• ​Very strong force of attraction between particles allowing solids to maintain their shape

​Liquids

• No definite shape but does have a specific volume

• ​Volume can change slightly based on temperature

• Weak force of attraction between molecules

• ​Particles can move but remain in contact with other particles

​Gases

• No definite shape or volume

• ​Volume can vary widely based on temperature

• ​Almost no force of attraction between molecules

• ​Particles move in all directions and collide with each other and the walls of a container

​Changes in State of Matter

​Most matter can exist in three different states depending on how much kinetic energy their particles have. An increase or decrease in energy can cause matter to change its state. This energy is most often in the form of thermal energy (heat).

How does Matter change state?

• ​Melting - Solid to Liquid

• ​Sublimation - Solid to Gas

• ​Vaporization - Liquid to Gas (could be boiling or evaporation)

• ​Freezing/Solidifying - Liquid to Solid

• ​Condensing - Gas to Liquid

• ​Deposition - Gas to Solid