1. What is the difference between an element and a compound?

2. Consider two objects that each weigh 20.0 g. One is made of lead and has a density of 11.4 g/mL. The second object is made of aluminum and has a density of 2.7 g/mL. Which object takes up more space? What volume does each occupy?

3. Use the periodic table to help you find the atomic symbol, atomic number, group number, number of protons, and number of electrons for these elements:

4. Describe nuclear fission and nuclear fusion.

5. What is an isotope? How can you figure out the most common isotope of an element?

6. Describe how you would use the periodic table to help you predict the type of bond between two atoms.

7. What are cations and anions?

8. Sort the following atoms into metals and nonmetals. Then name three ionic compounds that can be formed from some combination of these atoms.

9. Predict the type of bonding in each of the following substances. Provide their chemical names and predict which ones will conduct electricity.

10. Explain how you can determine the charge on a transition metal ion.

11. A substance does not dissolve in water and does not conduct electricity. What model of bonding accounts for these observations?

12. What is required to change one element into another element? Is it possible to do this in a laboratory?