| A | B |
|---|
| chemical symbol | the abbreviation for an element |
| nucleus | the positively charged center of an atom |
| portons, neutrons, electrons | major kinds of particles in an atom |
| protons | positively charged particles in the nucleus of an atom |
| neutrons | particles with no electrical charge in the nucleus of an atom |
| electrons | negatively charged particles in the energy levels surrounding the nucleus of an atom |
| two | number of electrons in the first energy level |
| atomic number | the number of protons in the nucleus of an atom |
| C | chemical symbol for carbon |
| H | chemical symbol for hydrogen |
