(Key to Section 1.2 Review)
1. D
2. C
3. B
4. D
1. A scientific study showed that the depth at which algae were found in a lake varied from day to day.
On clear days, the algae were found as much as 6 meters below the surface of the water but were only 1 meter below the surface on cloudy days. Which hypothesis best explains these observations?
A. Nitrogen concentration affects the growth of algae.
B. Rainfall affects the growth of algae.
C. Light intensity affects the growth of algae.
D. Wind currents affect the growth of algae.
2. Experiments may have only two variables; the “cause” variable and the “effect” variable. The
“cause”variable is known as the:
A. control.
B. independent variable.
C. constant.
D. dependent variable.
3. A scientist plants two rows of corn for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of water and light intensity. She checks the growth of the corn over a period of 3 months. Which of the following is a constant in this experiment?
A. plant height B. corn without fertilizer C. corn with fertilizer D. amount of water
4. An experiment testing a new asthma medication was set up with two groups. Group one was given a pill containing the new drug for asthma, while group two was given a sugar pill. The sugar pill serves as a:
A. control. B. constant. C. independent variable. D. dependent variable.
5. D
6. B
7. B
8. A
9. D
10. E
11. C
12. B
13. C
14. D
15. A
16. E
17. D
18. B
19. A
20. C
21. A
22. A
5. The first step in the scientific method involves:
A. forming a hypothesis.
C. performing an experiment.
B. making observations.
D. predicting the result of an experiment.
6. A pattern or relationship that has been established in a large amount of experimental data is a:
A. theory. B. hypothesis. C. law.
7. Ultimately, all scientific knowledge comes from:
A. experimentation. B. observation. C. textbooks. D. creative theory formation.
8. In order to be a scientific hypothesis, the hypothesis must be:
A. proven correct. B. simple. C. testable. D. popular.
9. A scientist testing the affect of a chemical on apple yield sprays an orchard with the chemical. A second orchard does not receive the chemical. In the fall, the number of apples harvested from each orchard is counted. Which of the following is the independent variable in this experiment?
A. the number of apples B. the chemical C. the treated orchard D. the untreated orchard
10. In order for the apple tree experiment in question 10 to be valid, both orchards must:
B. received the same amount of water.
D. all of these.
A. receive the same amount of sunlight.
C. have the same species of apply tree.
11. If a theory is challenged by new evidence, which of the following could occur?
A. the theory could be altered or replaced.
B. the evidence is discarded because it doesn’t agree with the theory.
C. a vote is taken on whether to accept the new evidence or not.
12. Eijkman fed a group of chickens exclusively on rice whose seed coat had been removed (polished rice or white rice). The chickens all developed polyneuritis (a disease of chickens) and died. He fed another group of chickens unpolished rice (rice that still had its seed coat). Not a single one of them contracted polyneuritis. He then gathered the polishings from rice (the seed coats that had been removed) and fed the polishings to other

chickens that were sick with polyneuritis. In a short time, the birds all recovered. Eijkman had accurately traced the cause of polyneuritis to a faulty diet. For the first time in history, a food deficiency disease had been produced and cured experimentally. Which of the following is a reasonable statement of Eijkman’s hypothesis?
A. Polyneuritis is a fatal disease for chickens.
B. White rice carries a virus for the disease polyneuritis.
C. Unpolished rice does not carry the polyneuritis virus.
D. The rice seed coat contains a nutrient that provides protection for chickens against polyneuritis.
E. None of these is a reasonable statement of Eijkman’s hypothesis.
Questions 13, 14, and 15 relate to the following paragraphs.
Scientist A noticed that in a certain forest area, the only animals inhabiting the region were giraffes. He also noticed that the only food available for the animals was on fairly tall trees, and as the summer progressed, the animals ate the leaves higher and higher on the trees. The scientist suggested that these animals were originally like all other animals, but generations of animals stretching their necks to reach higher up the trees for food, caused the species to grow very long necks.
Scientist B conducted experiments and observed that stretching muscles does NOT cause bones to grow longer, nor change the DNA of animals so that longer muscles would be passed on to the next generation. Scientist
B, therefore, discarded Scientist A’s suggested answer as to why all the animals living in the area had long necks.
Scientist B suggested instead that originally many different types of animals including giraffes had lived in the region but only the giraffes could survive when the only food was high in the trees, and so all the other species had left the area.
13. Which of the following statements is an interpretation, rather than an observation?
A. The only animals living in the area were giraffes.
B. The only available food was on tall trees.
C. Animals which constantly stretch their necks will grow longer necks.
D. A, B, and C are all interpretations.
E. A, B, and C are all observations.
14. Scientist A’s hypothesis was that:
A. The only animals living in the area were giraffes.
B. The only available food was on tall trees.
C. Animals which constantly stretch their necks will grow longer necks.
D. The animals which possess the best characteristics for living in an area, will be the predominant species.
E. None of the above are reasonable statements of Scientist A’s hypothesis.
15. Scientist A’s hypothesis being discarded is:
A. Evidence that the scientific method doesn’t always work.
B. A result achieved without use of the scientific method.
C: An example of what happened before the scientific method was invented.
D. An example of the normal functioning of the scientific method.
E. An unusual case.
1C 2B 3D 4A 5B 6C 7A 8C 9B 10D 11A 12D 13C 14C 15D
Section 2.1 Review Key: Observations 2,3,5,6,7,9, and 10 are qualitative observations.
Section 2.2 Review Key:
Prefix pico- nano- micro- milli- centi- deci- kilo-
Meaning
10 -12
10 -9
10 -6
10 -3
10 -2
10 -1
10 3
Symbol p n
 m c d k
Section 2.3 Review Key: 1 )meter 2)gram 3)liter: Volume in the metric system is a unit derived from cubic length... the liter is a cube that is 10.cm on each side. 4)FP=0 o C , BP=100 o C 5)FP=273 K , BP=373 K 6)No...too cold

1) A2 B4 C3 D2 E3 F3 G4 2) A22.1 B1.01 C19.84 3) A2.3 B17.95 C9890 D170
1)T=PV/nR 2)V=3.60cm
3 3)V
1
=P
2
V
2
/P
1
4)12.68kg/L 5)8.2796x10
10 mi/hr
1)A4.79x10
-5 B2.51x10
8 C4.26x10
3 D2.06x10
-3 2)6.0x10
7
3)2.5x10
4 4)4.2x10
-4 5)3.0x10
-6 6)1.5x10
12 7)1.4x10
-2
1)A is neither precise, nor accurate; B is both; C is precise, not accurate
2)Precise, not accurate 3)Accuracy=how close a measurement is to actual value. Precision is how close
Values for the same measurement are to each other 4)C 5)D 6)3.8% 7)8.50% 8)0.229%
1. Draw a tangent to the curve and find the slope of the tangent line.
2. a)
60
50
40
30
20
10
0
0 1
b) m = y
2
- y
1 x
2
- x
1 m =
32.8 - 10.2
2.9 - 0.9 m = 11.3g/mL
c) The slope represents the density of the unknown
3)
2 3
Volume (mL)
4 5 6
The graph is a curve, so draw the tangent and take the slope of the tangent:
Slope = -29 (mol/L)/minute
This slope represents how fast the concentration is changing.