Across
- 4. cannot be broken into simpler substances by chemical means
- 7. positively-charged
- 10. move around each other closely
- 11. mass of the protons and neutrons
- 12. negatively-charged
Down
- 1. indicates the number of protons and electrons
- 2. neutral
- 3. made of subatomic particles called, protons,electrons, and neutrons
- 5. vibrate in place
- 6. the amount of space and object takes up
- 8. moves around freely
- 9. anything that has mass and volume