Biology_Chapter_2_Test_Chemistry_of_Life_non ap2

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Name: _______________________________________Period: ___ Date: ____________

Biology
Chapter 2 Test
Chemistry of Life

Multiple Choice (2 points each)
Identify the choice that best completes the statement or answers the question.

____1. The three particles that make up atoms are
a. protons, neutrons, and isotopes. c. positives, negatives, and electrons.
b. neutrons, isotopes, and electrons. d. protons, neutrons, and electrons.

____2. The space surrounding the nucleus of an atom contains
a. protons. c. neutrons.
b. electrons. d. ions.

____3. If an atom contains 3 protons, 4 neutrons, and 3 electrons, its mass number would be
a. 3. c. 7.
b. 4. d. 11.

____4. Isotopes are atoms of the same element with the same number of protons and
a. a different number of electrons. c. a different number of neutrons.
b. a different number of molecules. d. the same number of neutrons.

____5. Which of the following is a use of radioactive isotopes?
a. can determine the ages of rocks and fossils
b. can be used to treat cancer and kill bacteria that cause food to spoil
c. can be used as “tracers” to follow the movements of substances within organisms
d. all of the above

____6. If an atom contains 11 protons and 12 neutrons, its atomic number is
a. 1. c. 12.
b. 11. d. 23.

____7. Which of the following terms describes a substance formed by the combination of two or more
elements in definite proportions?
a. compound c. nucleus
b. isotope d. enzyme

____8. Which of the following makes up a molecule of water?
a. one atom of hydrogen and one atom of oxygen
b. one atom of sodium and one atom of chlorine
c. one atom of hydrogen and two atoms of oxygen
d. two atoms of hydrogen and one atom of oxygen

Page 1
Name: _______________________________________Period: ___ Date: ____________

____9. Which of the following statements about a compound is true?
a. The physical and chemical properties of a compound are usually very different from
those of the elements from which it is formed.
b. Only the physical properties of a compound are usually the same as those of the
elements from which it is formed.
c. Only the chemical properties of a compound are usually the same as those of the
elements from which it is formed.
d. The physical and chemical properties of a compound are usually the same as those of
the elements from which it is formed.

____10. A covalent bond is formed as the result of
a. transferring electrons. c. transferring protons.
b. sharing an electron pair. d. sharing a proton pair.

____11. What type of electron is available to form bonds?
a. valence c. ionic
b. nucleus d. covalent

____12. What type of ion forms when an atom loses electrons?
a. neutral c. negative
b. positive d. possibly positive or negative

____13. Ice floats on water because
a. of cohesion. c. water shrinks when it freezes.
b. ice has a higher density than water. d. water expands when it freezes.

____14. The most abundant compound in most living things is
a. carbon dioxide. c. sodium chloride.
b. water. d. sugar.

____15. Water molecules are polar, with the
a. oxygen side being slightly positive and the hydrogen side being slightly negative.
b. oxygen and hydrogen sides being slightly positive.
c. oxygen and hydrogen sides being slightly negative.
d. oxygen side being slightly negative and the hydrogen side being slightly positive.

____16. A solution is a(an)
a. combination of isotopes.
b. chemical reaction.
c. evenly distributed mixture of two or more substances.
d. combination of two or more liquids.

____17. If you stir salt into boiling water, you produce a
a. mixture called a suspension. c. solution and suspension.
b. mixture called a solution. d. mixture only.

____18. When salt is dissolved in water, water is the
a. reactant. c. solute.
b. solution. d. solvent.

Page 2
Name: _______________________________________Period: ___ Date: ____________

____19. A map of eastern North America, showing the pH of rainfall in the various states, indicates that the
pH of rain in New York State varies from 4.22 to 4.40. According to these figures, the most acidic
rainfall in New York State has a pH of
a. 4.22. c. 4.35.
b. 4.30. d. 4.40.

____20. Solutions that contain concentrations of H+ ions lower than pure water
a. have pH values below 7. c. are bases.
b. are acids. d. are enzymes.

____21. A monosaccharide is a
a. carbohydrate. c. nucleic acid.
b. lipid. d. protein.

____22. Which statement is true?
a. Simple sugars are made of polysaccharides.
b. Glycerol is made of fatty acids.
c. DNA molecules are made of nucleotides.
d. Amino acids are made of proteins.

____23. When hydrogen and oxygen combine to form water, water is
a. a product. c. both a product and a reactant.
b. a reactant. d. neither a product nor a reactant.

____24. Identify the reactant(s) in the chemical reaction, CO2 + H2O  H2CO3.
a. CO2, H2O, and H2CO3 c. H2CO3
b. CO2 and H2O d. CO2

____25. What is the process that changes one set of chemicals into another set of chemicals?
a. cohesion c. chemical reaction
b. adhesion d. dissolving

____26. What is the term used to describe the energy needed to get a reaction started?
a. adhesion energy c. cohesion energy
b. activation energy d. chemical energy

____27. Chemical reactions that release energy
a. will not occur. c. will always explode.
b. will never explode. d. often occur spontaneously.

____28. A substance that accelerates the rate of a chemical reaction is called a(an)
a. catalyst. c. molecule.
b. lipid. d. element.

____29. Suspensions are mixtures
a. of water and nondissolved material.
b. in which the components are evenly distributed throughout the solution.
c. both a and b
d. neither a nor b

Page 3
Name: _______________________________________Period: ___ Date: ____________

____30. Which of the following organic compounds is the main source of energy for living things?
a. carbohydrates c. nucleic acids
b. lipids d. proteins

Modified True/False (3 points each)
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the
statement true.

____31. The basic unit of matter is the molecule. _________________________

____32. Water is the greatest solute in the world. _________________________

____33. Lipids are important parts of biological membranes and waterproof coverings.
______________________

____34. Proteins that speed up the rate of chemical reactions in the cell are antibodies.
_________________________

Completion (2 points each)
Complete each statement.

35. The elements sodium and __________ combine to form the compound commonly called table salt.

36. A chemical bond formed by the transfer of electrons is a(an) ____________________ bond.

37. The pH scale is a measurement system that indicates the concentration of ____________________ in
solution.

Short Answer (4 points each)

38. What are the four groups of organic compounds found in living things?

__________________________________________________________________________________

Page 4
Name: _______________________________________Period: ___ Date: ____________

Science Skills:

Science Skills (5 points each)

pH Values of Some Common Substances
Substance pH
Hydrochloric acid 1.0
Sulfuric acid 1.2
Tomatoes 4.2
Rainwater 6.2
Pure water 7.0
Sea water 8.5
Ammonium chloride 11.1
Sodium hydroxide 13.0

Table 1

39. What is the strongest acid listed in Table 1?

40. What is the pH of the weakest acid listed in Table 1?

41. What is the pH of the strongest base listed in Table 1?

42. Using your knowledge of the pH scale, which of the chemicals in Table 1 has the lowest concentration of
H+ ions?

43. A change of one unit on the pH scale represents a tenfold increase in the concentration of hydrogen ions.
According to the pH values listed in Table 1, how much greater is the H+ ion concentration in tomatoes
than in rainwater?

Page 5
Name: _______________________________________Period: ___ Date: ____________

Essay (8 points each)

44. Compare protons, electrons, and neutrons with respect to location within atoms and electric charge.

_______________________________________________________________________________

Extra Credit (up to 5 points)

45. Compare enzyme activity to a lock and key.

_______________________________________________________________________________

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