Chapter 2 (Part I) Reading Study Guide
Human Biology (BIOL 164)
I.
Chapter 2 (Part I): Chemistry Comes to Life (pp. 14-24)
A. Important Terms
Atoms
Nonpolar covalent bonds
Base/Basic
Subatomic particles
Molecule
pH scale
Protons
Molecular formula
Hydrogen ion
Neutrons
Ions
Hydroxide ion
Electrons
Ionic bond
Concentration
Elements
Polar
Buffers
Atomic number
Nonpolar
Solution*
Atomic weight
Hydrophilic*
Solute*
Periodic table
Hydrophobic*
Solvent*
Compound
Hydrogen bond
-Chemical bonds
Water
-Covalent bonds (Single,
Noble gases*
-Double, and Triple)
Polar covalent bonds
Acid/Acidic
- See the StudyMate activities for definitions of these terms.
B. Figures: 2.1, 2.2 (Only know the element symbols specified in the questions below), 2.7-2.11,
and 2.13
C. Tables: 2.1, 2.2, and 2.3
D. Highlighting the Concepts (p. 34): The Nature of Atoms, Compounds and Chemical Bonds,
and The Role of Water in Life
E. Reviewing the Concepts (p. 35): 1, 2, 5, 7, and 25.
F. Biology of Humans Web Site Resources:
1. Web Activity: Atoms, Ions, and Bonding
2. Web Activity: Water and Chemistry
3. Practice Quizzes (Only questions dealing with this portion of chapter 2).
G. Additional Study Questions
1. What is the general physical structure of an atom, in terms of the three major subatomic
particles and their relative locations?
2. What term is defined as “a form of matter containing only one kind of atom”?
3. What information about numbers of subatomic particles is provided by the atomic number?
4. What information about numbers of subatomic particles is provided by the atomic weight?
5. If you subtract the atomic number from the weight number, what is the interpretation of the
answer? (e.g. for Nitrogen: 14-7=7; Hint: Think of a subatomic particle.)
6. Give the chemical symbol for the following elements: Hydrogen, Chlorine, Calcium,
Carbon, Nitrogen, Oxygen, and Sodium.
7. Using the section of the periodic table shown in figure 2-2, state the element(s) that has/have:
a. An atomic number of 12
b. An atomic weight number of 31
c. Eight protons in each atom
d. Sixteen neutrons in each atom
e. Eleven electrons in each atom
8. True or False: If you change the number of protons that are present in an atom, then you
have changed the type of atom/element.
9. Why, in terms of subatomic particles, are atoms of elements "electrically neutral" (i.e. the
overall electrical charge is zero)? Hint: View the “Charge” category in table 2.1.
10. What is an ion? How do atoms become ions, with respect to subatomic particles?
11. Why are atoms willing to gain or lose elections to become ions? You should refer to the
periodic table and column 8A (Noble gases; Figure 2.2). Hint: Watch the video clips for the
answer.
12. Which atomic particle interacts between atoms to form a chemical bond?
13. What two pieces of information are provided by the molecular/chemical formula of a
compound (e.g. H2O)?
14. What is a molecule?
15. What are the three types of chemical bonds discussed in your textbook? Which (one) of
these types of bonds is/are based on equal sharing of electrons? Which (one) of these types of
bonds is/are based on transfer of electrons? Which (one) of these types of bonds is/are based on
unequal sharing of electrons?
16. Explain the following symbolism: a) Na+1 b) Cl-1 c) Mg+2
17. Distinguish between single, double, and triple covalent bonds.
18. Distinguish between a polar and nonpolar covalent bond.
19. Distinguish between the terms "hydrophilic" and "hydrophobic" (You may need to look
these terms up in a dictionary or glossary). Classify each of the following substances as
hydrophilic or hydrophobic: sugar, salt, and cooking oil.
20. Are polar molecules classified as hydrophilic or hydrophobic? Are nonpolar molecules
classified as hydrophilic or hydrophobic? Explain your responses.
21. Explain the phrase "Water is a good solvent". Why would this property of water be
important to you (in a biological sense)? Distinguish between a solute and a solvent.
22. What is the purpose of the pH scale and how is it organized? You should refer to figure
2.13 on p. 23 to facilitate your explanation.
23. What does “concentration” refer to? Your response should include the terms solute, solvent
and solution.
24. What is true of the relative concentrations of hydrogen ions (i.e. H+1) and hydroxide ions
(i.e. OH-1) at pH 7?
25. As the concentration of hydrogen ions in a solution increases, what happens to the pH
number? As the concentration of hydroxide ions in a solution decreases, what happens to the pH
number?
26. The pH of solution A is 4 and the pH of solution B is 3. Solution B has ____ (0.5, 1, 10,
100, or 1000 ) times _____ (more, less) H+1 ions than solution A.
27. Classify each of the following pH values as acidic, basic, or neutral: a. 9 b. 4 c. 6 d. 7 e. 12
28. What is the function of a buffer?