Across
- 2. average mass of the naturally occurring isotopes of an element
- 4. no electrical charge
- 6. equal to the number of protons plus neutrons.(3 words)
- 8. Move around the outside of the nucleus
- 9. have a positive charge (+) and Located in the nucleus of the atom
Down
- 1. Electrons move in definite orbits around the nucleus
- 3. Have the same atomic number Have different atomic mass numbers
- 5. An atom that carries an electrical charge
- 6. number of protons
- 7. often used for things that are too small or too large to be observed or that are too difficult to be understood easily