Across
- 2. How easily a substance reacts with others.
- 4. Atoms of the same element with different numbers of neutrons.
- 7. An element found in all living things.
- 8. A negatively charged particle around the nucleus.
- 11. The smallest unit of an element.
- 12. A neutral particle in the nucleus.
Down
- 1. force The force between charged particles.
- 3. A positively charged particle in the nucleus.
- 5. The outside area of an object.
- 6. Simple Crossword Clue
- 7. The electric property of a particle (positive or negative).
- 9. A prefix meaning one billionth.
- 10. The amount of space an object takes up.