Across
- 3. Number of protons does not change in
- 6. equal to the number of protons plus neutrons
- 7. any of the possible energies an electron may have in an atom
- 9. have no electrical charge
- 10. have a negative electrical charge
Down
- 1. an electron in the outermost energy level of an atom
- 2. number of protons
- 4. the number of protons for a given atom never changes
- 5. average mass of the naturally occurring isotopes of an element
- 8. have a positive charge