Across
- 3. Large and heavy like protons and no electrical charge.
- 6. Number of protons.
- 8. Any of the possible energies an electron may have in an atom.
- 10. Equal to the number of protons plus neutrons.
Down
- 1. Much larger and heavier than electrons and a positive charge.
- 2. Average mass of the naturally occurring isotopes of an element.
- 4. An electron in the outermost energy level of an atom.
- 5. Two atoms with different numbers of neutrons are called.
- 7. Tiny very light particles.
- 9. An atom that carries an electrical charge is called an.