Victory for the ACT Student Text 15e

300 • S CIENCE

DATA REPRESENTATION STRATEGIES

23. Compared to the ocean water below it, the salinity of sea ice in contact with seawater is: A. higher than that of the seawater. B. about the same as that of the seawater. C. lower than that of the seawater. D. sometimes lower and sometimes higher than that of the seawater. The salinity of the ice at the surface of the slab is equal to the salinity of the: F. sea ice at a depth of approximately 1.5 cm. G. sea ice at a depth of approximately 7.0 cm. H. sea ice at a depth of approximately 9.0 cm. J. water beneath the sea ice. According to the information provided, –Š‡ ˆ”‡‡œ‹‰ –‡’‡”ƒ–—”‡ ‘ˆ ’—”‡ ™ƒ–‡” ‹• approximately: A. 2 degrees lower than that of seawater. B. 0.2 degrees lower than that of seawater. C. 3.5 degrees higher than that of seawater. D. 2 degrees higher than that of seawater. According to Figure 2, the salt content of the sea ice: F. equals 0. G. is constant at all depths. H. decreases, then increases with depth. J. increases, then decreases with depth. 27. The researcher takes a 1 gram sample of ice from a depth of 10 cm, and wishes to take a sample of ice from a depth of 1.3 cm that will contain the same weight of total salts. Approximately how large a sample is needed? A. 0.25 grams B. 1.0 gram C. 4.0 grams D. 10.0 grams 24. 25. 26.

PASSAGE V Seawater contains dissolved salts. • ƒ ”‡•—Ž–ǡ •‡ƒ™ƒ–‡” ˆ”‡‡œ‡• ƒ– ƒ Ž‘™‡” temperature than freshwater (Figure 1).

The Cambridge Edge Use the following approach for Data Representation passages: 1. Preview the passage and items 2. Underline and circle key words 3. Pay attention to scales, units, legends, and other keys to understanding graphs and charts 4. Pay attention to axes on graphs 5. Pay attention to data trends Passage Perfect When a passage includes two graphs, you may be asked to use information from both graphs to answer a single question. As you preview the graphs, pay attention to any similarities and differences between them.

Š‡ •‡ƒ™ƒ–‡” ˆ”‡‡œ‡•ǡ ƒ• –Š‡ ™ƒ–‡” molecules begin to form their characteristic ring-like structures, the salt ions, primarily sodium and chloride, are forced out of solution and form pockets of salt. The brine (salty water) leaches out of the bottom of the ice into the water below. Thus, sea ice, when melted, is generally considerably less saline than the original seawater. The solid-line graph below indicates the percentage of salt in a slab of ice that lies over seawater on a cold ocean surface (Figure 2). Figure 1 Sea Ice Salinity

Figure 2