| Term | Definition |
|---|---|
| matter | everything that has mass and takes up space. |
| atom | small particle that is the building block of all matter |
| substance | matter with a composition that is always the same |
| element | a pure substance made up of only one kind of atom |
| molecule | two or more atoms that are held together by chemical bonds and act as a unit |
| compound | substance made of two or more elements that are specifically joined in a specific combination |
| mixture | matter that can vary in composition |
| heterogenous mixture | mixture in which the substances are not evenly mixed |
| homogenous mixture | a mixture in which two or more substance are evenly mixed but not bonded together |
| physical change | a change in size, shape, form or state of matter that does not change the matter’s identity |
| chemical change | a change in matter in which the substances that make up the matter change into other substances with different physical and chemical properties |
| law of conservation of mass | states that the total mass of a chemical reaction is the same as the total mass after the chemical reaction |
