When you have completed this chapter you should be able to: 1. Distinguish among the three classes of matter: elements, compounds, and mixtures.
2. State the law of definite proportions.
3. Explain the meanings of the letters, numbers, and parentheses in the chemical formula of a compound, for instance, Al2(SO4)3.
4. Compare the properties of metals and nonmetals.
5. List some of the characteristic properties of the halogens, the alkali metals, and the inert gases.
6. State the periodic law and describe how the periodic table is drawn up.
7. Distinguish between the groups and periods of the periodic table.
8. State what is meant by atomic shells and subshells.
9. Distinguish between metal and nonmetal atoms in terms of their electron structures.
10. Explain the origin of the periodic law in terms of the electron structures of atoms.
11. Compare covalent and ionic bonds.
12. State what is meant by a polar covalent molecule.
13. Discuss the nature of an atom group.
14. Explain what a chemical equation represents and does not represent.
15. Recognize whether a chemical equation is balanced or unbalanced.
16. Balance an unbalanced chemical equation.