| A | B |
|---|
| Proton | a positively charged subatomic particles that is found in the nucleus of an atom |
| Electron | a negatively charged subatomic particle that is found in the space outside the nucleus of an atom |
| Neutron | a neutral subatomic particle that is found in the nucleus of an atom |
| Atomic Number | a unique number for each element that equals the number of protons in an atom of that element |
| Mass Number | the sum of the numbrt of protonsand neutrons in the nucleus of an atom |
| isotopes | atoms of a given element that have different numbers of neutrons and different mass numbers |
| Energy levels | the possible energies that electrons in an atom can have |
| Electron cloud | a visual model of the most likely locations for the electrons in an atom |
| orbital | a region of space around the nucleus where an electron is liekly to be found |
| electron configuration | the arrangement of electrons in the orbitals of an atom |
| ground state | a state which all the electrons in an atom have the lowest possible energies |
