LATER PASSAGES: ANSWERS AND EXPLANATIONS
Passage I
1 . C In Figure 1, all four anions follow the same trend, so eliminate (B) and (D) immediately.
From left to right in the graph, the concentration of condensation nuclei is increasing for all
four anions, and as this value increases, the average number of tracks decreases for all four
anions. Only (C) accurately reflects this trend.
2 . G Read if and only when a question can’t be answered from the figures. The introduction
provides the order of development, correctly described in (G).
3 . C Notice from the answer choices that this question has two components: time to maximum
magnetic force and maximum magnetic force itself. Notice also that all the answer choices
focus on the ethanol vapor. According to Figure 2, the ethanol vapor took about 40 minutes
to reach its maximum magnetic force, whereas the water vapor took only about 15 minutes.
Therefore, the ethanol vapor took more time, eliminating (B) and (D). The ethanol vapor
reached a maximum magnetic force of approximately 4.25 Newtons, while the water vapor
reached a maximum magnetic force of approximately 4.75 Newtons. Therefore, the ethanol
vapor’s magnetic force reached a lesser maximum strength, eliminating (A) and making (C)
the correct answer.
4 . H Note the axes on each of the graphs. Magnetic force appears only in Study 2, which
eliminates (G) and (J) immediately. Then, since magnetic force is the primary focus of Study
2, eliminate (F) because it contains no mention of magnetic force. Only (H) remains and
contains accurate information regarding both studies.
5 . D This requires a bit of logical thinking and some outside knowledge. Only Study 2 is
concerned with water vapor, whereas the general introduction discusses alcohol vapor.
Therefore, it can be inferred that the entire experiment deals with alcohol vapor, making
changes in water vapor only partially relevant, eliminating (A) and (C). Then, between the
two answer choices, which is more likely to be the case at temperatures below −150°C?
Alcohol in this temperature range is colder and therefore more likely to be solid than vapor.
Only (D) reflects this information correctly.
6 . G According to Table 1, 75–80% of all four types of anions fit in to the 0.1–0.5 category, or the
smallest charge category. There are no exceptions in Table 1, so the only answer choice that
can work is (G).
