Across
- 5. A substance that consists of atoms that all have the same number of protons
- 7. Neutral charge (no charge) Mass 1
- 9. Ability to react with other elements
- 10. The electrons in the energy level
Down
- 1. Anything that has mass and takes up space (has volume)
- 2. Positive charge Mass of 1
- 3. Negative charge Mass of 0
- 4. Was developed based on the physical and chemical properties of the known elements
- 6. The Smallest unit of matter
- 8. Center of a atom