| A | B |
|---|
| nucleus | 1 (cell) The organelle that controls all of a cell's activities 2(atom) The center of an atom |
| proton | A subatomic particle with a positive charge |
| neutron | A subatomic particle with no charge |
| electron | A subatomic particle with a negative charge |
| element | A substance made up of only one kind of atom |
| atom | The smallest unit of an element that has all the properties of that element |
| molecule | A grouping of two or more atoms joined together |
| periodic table | The table of elements in order of increasing atomic number,grouped by similar properties |
| compound | A substance made of the atoms of two or more different elements |
