1. State the number of valence electrons for a hydrogen atom and a chlorine atom.

2. State the number of valence electrons for a hydrogen atom and a chlorine atom in a covalent bond.

Use the periodic table to predict an ionic charge for each of the following metal ions.

3. Be ion

4. Cs ion

5. Ga ion

6. Pb ion

Use the periodic table to predict the ionic charge for each of the following nonmetal ions.

7. I ion

8. S ion

9. Se ion

10. P ion

Write out the electron configuration for each of the following nonmetal ions.

11. Br -

12. O2-

13. Se2-

14. N 3-

15. What is the general trend in electronegativity across a series in the periodic table?

16. Which elements are more electronegative, semimetals of nonmetals?
State whether the representative particle in each of the following substances is an atom, a molecule, or a formula unit.

17. plutonium, Pu

18. ozone, O3

19. plutonium(III) oxide. Pu2O3

20. Explain why the radius of a chloride ion (0.181 nm) is about twice that of chlorine atom (0.099 m).