| Term | Definition |
|---|---|
| atom | smallest part of an element |
| element | simple substance that can not be broken down into simpler substances |
| compound | substance made up of 2 or more elements chemically combined |
| molecule | smallest part of an substance |
| chemical symbol | represents the first letter(s) of an element |
| chemical formula | formula that shows the elements that make up a compound |
| subscript | number in a chemical formula that shows how many of each atom are in one molecule of a compound |
| Oxygen | O |
| Nitrogen | N |
| Aluminum | Al |
| Iron | Fe |
| Sodium | Na |
| Hydrogen | H |
| Carbon | C |
| Helium | He |
| Lead | Pb |
| Mercury | Hg |
| Water | H2O |
| Carbon Dioxide | CO2 |
| Iron sulfide | FeS2 |
| Silica | SiO2 |
| Hydrogen Peroxide | H2O2 |
