FROM GLASSES TO GASES: The Science of Matter - Glossary

atom

There are 92 different kinds of atoms in nature. All substances are made of atoms or of combinations of atoms called molecules.

density

The amount of matter, or mass, in a unit volume. Density measures how concentrated a piece of matter is.

detergent

A cleaning substances. More detergents are continually being developed to remove grease and dirt more effectively.

elasticity

A measure of the springiness of a material. A substance with high elasticity can be stretched quite far and still return to its original shape.

insoluble

A substance is insoluble if it will not dissolve in a particular liquid. A substance may be soluble in one liquid but insoluble in another.

matter

Anything that takes up space. This includes all solids, liquids, and gases.

metal fatigue

The weakness that may develop in a piece of metal that undergoes repeated stretching or vibration. It begins when small cracks develop on the metal's surface.

molecule

The smallest part of a substance that still has the chemical properties of that substance. A molecule consists of atoms joined together.

plastic liquid

A liquid that will only flow when pushed or squeezed.

solubility

A measure of how well a substance dissolves in a particular liquid. The solubility may be different in one liquid (e.g., water) than in another (e.g., alcohol).

solution

A mixture of a liquid and one or more other substances. These other substances may be solids, liquids, or gases.

solvent

The liquid in which a substance is dissolved.

state

The condition of a piece of matter – whether it is a solid, a liquid, or a gas.

surface tension

The force acting across the surface of a liquid that makes the liquid seem to have an elastic skin. It is caused by unbalanced forces between molecules at the surface.