the average kinetic energy of the atoms or molecules within a substance

a scale that measures temperature and puts the boiling and freeing points of water exactly 180 degrees apart. Invented by Physicist Daniel Fahrenheit.

also called centigrade scale is based on 0 degrees for the freezing point of water and 100 degrees for the boiling point of water. Invented by Astronomer Anders Celsius.

a state of matter in which atoms are closely spaces and vibrate in a fixed position. It has a fixed shape and volume.

a state of matter in which atoms are constantly moving around and bumping into each other. It flows freely but has a constant volume

a state of matter in which atoms vibrate so much that they are far apart. They expand freely to fill the whole of a container, it has no fixed shape and no fixed volume

two or more atoms bonded together

measure of the mass per unit volume; tells how compact a substance is.

when matter changes from one state (solid, liquid, gas, plasma) to another.

the amount of space a substance occupies

phase change from the gaseous state into the liquid state

phase change from the liquid state to the gaseous state.

phase change from the solid state to the gaseous state without passing through the liquid state

phase change from the liquid state to the solid state when its temperature is lowered below its freezing point.

phase change from a solid to a liquid.

phase change from the gaseous state to a solid, without passing through the liquid state