Atoms + Ions

4. The number of valence electrons in a Group 17 element.
6. The Period number of sodium.
8. A number for each vertical column of the Periodic Table. Shows the number of valence electrons
9. A negatively charged subatomic particle found in shells orbiting the nucleus of an atom.
12. A short way of writing how many electrons are in each shell.
14. A neutrally charged particle that contains an equal number of protons and electrons.

1. Electrons in the outer-most shell.
2. The number of total subatomic particles in the nucleus of an atom.
3. An uncharged subatomic particle found in the nucleus of an atom.
5. An element which has the electron configuration: 2,5.
7. A number for each horizontal row of the Periodic Table. Shows the total number of electron shells.
10. A positively charged subatomic particle found in the nucleus of an atom.
11. The number of protons in atom. Also equal to the number of electrons.
13. An atom that has gained or lost valence electrons, to have a full outer shell and be stable.