Across
- 3. a material that lets electricity flow through it
- 4. physical substance in general
- 6. number: the number of protons in the nucleus of an atom
- 7. hard but easy to break
- 9. subatomic particle about the same mass as a proton
- 10. stable subatomic particle in all atomic nuclei
Down
- 1. atoms as a source of nuclear energy
- 2. important part of an object
- 5. mass: The atomic mass of a single atom or total mass
- 8. a stable subatomic particle with a charge of negative electricity