Across
- 1. vertical columns on periodic table
- 3. positively charged ion
- 5. element with one proton
- 6. atoms with different number of neutrons (same element and number of protons)
- 7. negatively charged ion
- 8. electrons orbit around
Down
- 2. horizontal rows of the periodic table
- 4. alkali metal
- 5. noble gas
- 6. atom gains or loses electrons