| A | B |
|---|
| Atom | smallest part of an element |
| Element | substance made of one type of atom |
| proton | positively charged particle in the nucleus |
| neutron | neutrally charged particle in the nucleus |
| electron | negatively charged particle that orbits the nucleus |
| Atomic Mass | combined mass of protons and neutrons |
| Atomic number | number of protons in an atom |
| Periodic Table | List of all elements organized by atomic number |
| molecule | two or more atoms bonded together |
| compound | two or more elements bonded together |
| nucleus | center of an atom; contains protons and electrons |
| chemical | a purified/prepared substance |
