Across
- 3. any of the possible energies an electron may have in an atom
- 4. equal to the number of protons plus neutrons
- 6. has a negative electrical charge
- 7. average mass of the naturally occurring isotopes of an element
- 9. an element with one proton, zero neutrons, and one electron
- 10. the the atomic number for carbon
Down
- 1. an electron in the outermost energy level of an atom
- 2. has no electrical charge
- 5. has a positive electrical charge
- 8. the atomic number for lithium