Science ACT Practice

Sound energy is transported through a medium by sound waves. The speed with which sound waves move through a medium is the speed of sound, V_s, for that medium.

This table gives V_s at 298 K for 3 metals having different d:

Are the data in the Table consistent with the hypothesis that as d for metals increases, V_s for metals increases only?

• Yes, because the Table shows that V_s is greater when d equals 2.7 g/cm³ than when d equals 11.3 g/cm³, and that V_s is greater when d equals 11.3 g/cm³ than when d equals 19.3 g/cm³.

• Yes, because the Table shows that V_s is greater when d equals 11.3 g/cm³ than when d equals 2.7 g/cm³, and that V_s is greater when d equals 19.3 g/cm³ than when d equals 11.3 g/cm³.

• No, because the Table shows that V_s is greater when d equals 2.7 g/cm³ than when d equals 11.3 g/cm³.

• No, because the Table shows that V_s is greater when d equals 11.3 g/cm³ than when d equals 19.3 g/cm³.

Answer explanation

Getting to the Answer: Identify the relationship between d and V_s in the Table to determine if the data are consistent with the hypothesis that as d for metals increases, V_s increases only. According to the Table, as d increases from 2.7 to 11.3 to 19.3 g/cm³, V_s decreases from 6,400 to 2,000 and then increases to 3,200 m/sec. Therefore, the data are not consistent with the hypothesis. Eliminate (A) and (B), and then compare the statements in (C) and (D) to the Table to determine which matches the data.

Tags

NGSS.HS-PS4-1

Because amphibian eggs lack a hard outer shell, their DNA can be damaged by exposure to ultraviolet (UV) radiation in sunlight. The following figure shows the percent of eggs that survived to hatching in the lab for these 7 species after exposure to unfiltered sunlight or to sunlight from which the UV radiation had been filtered out.

Based on the information in the Figure, eggs from which species are most likely to survive prolonged exposure to sunlight?

• Species A

• Species C

• Species F

• Species G

Tags

NGSS.HS-LS4-5

When water droplets containing dissolved ions freeze, opposite charges may develop between the newly formed ice crystals and the still unfrozen droplets. As the ice crystals and droplets separate in a cloud, charged regions form.

Solutions of four sodium (Na) salts, containing fluoride (F^-), chloride (Cl^-), bromide (Br^-), and iodide (I^-) ions, were each made at six different concentrations, in moles per liter (moles/L). The solutions were slowly cooled until freezing began. The electrical potential (whether the droplets had a positive or negative charge with respect to the ice crystals) was measured in volts. The results are shown in the Figure.

A scientist could best determine which ion (F^-, Cl^-, Br^-, or I^-) produced the greatest electrical potential in the Experiment by comparing the electrical potential that develops between ice and:

• a solution of each sodium salt at the same concentration.

• a single sodium salt solution at different concentrations.

• a single sodium salt solution at different temperatures.

• droplets of sodium salt solutions at different collision rates.

Tags

NGSS.HS-PS1-5

Herbicides are used to control the growth of weeds. An herbicide that may be used safely with one crop species may damage another crop if the latter crop is planted in soil containing residual amounts of the herbicide from an earlier application. The following experiment was performed to study this effect:

A botanist filled 90 pots with Soil Type 1. No herbicide was added to the soil in 10 pots. The other pots were divided into groups of 10 and the soil in each group was treated with 10, 20, 50, or 100 ppm of either Herbicide A or B. All other factors were held constant. Ten seeds of a corn hybrid were planted in each pot. After 40 days, the plants were uprooted, oven-dried, and weighed. The results are shown in the following table:

Which of the following sets of plants served as the control in the experiment?

• Plants grown in untreated soil

• Plants grown in soil treated with 10 ppm of Herbicide A

• Plants grown in soil treated with 10 ppm of Herbicide B

• Plants grown in soil treated with 100 ppm of Herbicide A

Tags

NGSS.HS-LS2-2

NGSS.HS-LS4-5

As the Sun's activity increases, the number of sunspots increases, as does the flux (flow rate across a 1 m² area) of radiation and of charged particles that Earth receives from the Sun. The figure below shows A_p, a measure of the activity of Earth?s magnetic field. A_p increases as the flux of charged particles Earth receives from the Sun increases.

A geomagnetic storm in Earth's magnetic field is indicated by an A_p greater than or equal to 30 nT. According to the Figure, a geomagnetic storm occurred at some time during each of how many years, if any, of the 13-year period?

• 0

• 1

• 12

• 13

Tags

NGSS.HS-ESS3-5

NGSS.HS-PS2-5

Seashore cliffs often lose rock or sediment to wave erosion. The Figure shows cliff compositions; cliff heights, in meters (m); and the net change in mean high water mark (MHWM), in m, from 1880 to 1970 along a section of shoreline. A net negative change in MHWM indicates a net loss of' rock or sediment and a net positive change indicates a net gain of sediment.

The following table shows the percentage of a year that vertical sections of a cliff are exposed to wave erosion:

Based on the information in the Table, a cliff section with a height of 4.0-4.5 m above the zero baseline would be exposed to wave erosion approximately what percentage of a year?

• 10%

• 2%

• 0.8%

• 0.3%

Tags

NGSS.MS-ESS2-2

Solar cycles are periodic variations in the Sun's brightness. The following figure shows the number of sunspots and the Sun's brightness at a particular wavelength for part of one cycle.

Based on the Figure, which of the following hypotheses best relates the number of sunspots to the Sun's brightness at the particular wavelength?

• The number of sunspots is highest when the Sun is near its maximum brightness.

• The number of sunspots is lowest when the Sun is near its maximum brightness.

• The number of sunspots is highest both when the Sun is near its maximum brightness and when the Sun is near its minimum brightness.

• The number of sunspots is lowest both when the Sun is near its maximum brightness and when the Sun is near its minimum brightness.

The following statements are a scientist's opinion.

Chlorine (Cl₂ ) should not be used to disinfect public water supplies. Water supplies contain bacteria and viruses as well as natural organic matter. Organic by-products are formed when chemical reactions between Cl₂ and natural organic matter occur. These by-products should not be in public water systems because they are hazardous and can be toxic to humans.

Any Cl₂ left in water after disinfection is then consumed by the public. The excess Cl₂ can react with the components of saliva, stomach fluid, and food, thus forming new by-products which could also be toxic.

Which of the following statements would support the scientist's opinion concerning the formation of hazardous substances by Cl₂ ? Hazardous substances are:

• formed when Cl₂ is mixed with saliva.

• formed when Cl₂ is mixed with ozone.

• not formed when Cl₂ is mixed with food.

• not formed when Cl₂ is mixed with saliva.

Tags

NGSS.HS-ESS3-4

Sound energy is transported through a medium by sound waves. The speed with which sound waves move through a medium is the speed of sound, V_s, for that medium.

This table gives V_s at 298 K for 3 metals having different d:

Are the data in the Table consistent with the hypothesis that as d for metals increases, V_s for metals increases only?

• Yes, because the Table shows that V_s is greater when d equals 2.7 g/cm³ than when d equals 11.3 g/cm³, and that V_s is greater when d equals 11.3 g/cm³ than when d equals 19.3 g/cm³.

• Yes, because the Table shows that V_s is greater when d equals 11.3 g/cm³ than when d equals 2.7 g/cm³, and that V_s is greater when d equals 19.3 g/cm³ than when d equals 11.3 g/cm³.

• No, because the Table shows that V_s is greater when d equals 2.7 g/cm³ than when d equals 11.3 g/cm³.

• No, because the Table shows that V_s is greater when d equals 11.3 g/cm³ than when d equals 19.3 g/cm³.

Tags

NGSS.HS-PS4-1