Across
- 3. number of protons
- 7. The reactivity of metals
- 9. attraction of the nucleus and electrons and repulsion of electrons.
- 10. the tendency of an atom to lose electrons.
- 12. Vertical line on periodic table.
Down
- 1. distance from nucleus to outermost electron.
- 2. the tendency of an atom to attract electrons towards itself
- 4. located mainly at the middle of the periodic table.
- 5. Located on periodic table staircase.
- 6. Located mainly top right of periodic table.
- 8. energy needed to remove a electron from a isolated atom.
- 11. Horizontal line on periodic table