States of Matter/Changes of State

States of Matter

The physical forms matter can take.

Changes of State

The change of matter from one state or phase to another. There are 6!


Energy is added to change a solid into a liquid


Energy is removed to change a liquid into a solid


Energy is added to change a liquid into a gas


Vaporization that occurs at the surface of a liquid and can occur at any temperature.


Vaporization that occurs throughout a liquid and occurs at high temperatures. The pressure in the liquid must match the pressure above the liquid.


Energy is removed to change a gas into a liquid.


Energy is added to change a solid directly into a gas.


Energy is removed to change a gas directly into a solid. (example: frost)


Has a definite shape and volume and the particles very little kinetic energy but vibrate in place.


Has a definite volume but no definite shape. The particles have a medium amount of kinetic energy and can slide past one another.


Has NO definite shape or volume. The particles have a lot of kinetic energy and move anywhere.

Kinetic Theory of Matter

The kinetic theory of matter states that all matter is made of small particles that are in random motion and that have space between them. This means that no matter what phase matter is in, it is made of separate, moving particles.


Anything that has mass and takes up space


the amount of matter in an object


The amount of space an object takes up

Temperature during a phase change

stays the same