The Chemical Context of Life
Campbell Chapter 2

1. Which six elements make up almost all of living matter?

2. Give the chemical symbols, atomic number, and atomic mass of each of these elements.

3. Which elements account for most of the remaining percentage? (These total less than 2%)

4. What are trace elements? Name some of them.

5. What does the atomic number tell you about the atomic structure of any element?

6. Briefly describe each subatomic particle, its approximate weight (in a.m.u.)and charge.

7. How do you find the mass of an atom?

8. Explain the term isotope.

9. How may radioactive isotopes be useful in biological research?

10. Compared to ³¹P, how does the radioactive isotope ³²P differ?

11. What are energy levels? Orbitals?

12. What is the relationship between electron energy and its distance from the nucleus?

13. Name the orbitals which may be present in each electron energy level, and the order in which they might occur.

14. How many electrons may occupy an orbital?

15. What is a valence electron? What are the valences of each of the six most common elements?

16. Explain the nature of a covalent bond.

17. Differentiate between polar and nonpolar covalent bonds. Give an example of each.

18. What determines if a particular covalent bond is polar or nonpolar?

19. Describe the nature of ionic bonds.

20. Describe hydrogen bonds and how they form. Explain their significance to biological systems.

21. What is the significance of a molecule's shape?