Question

Passage describes a science experiment and a

student's observations at the end of the experiment.
student follows the following procedure for modeling
the water cycle.
1. Fill a clear plastic cup about half full with water.
2. Tint the water with a few drops of purple food
dye.
3. Seal the cup with a clear plastic lid, and then
place the cup by a sunny window.
4. After 30 minutes, place an ice cube on the top of
the lid.

After following the procedure, the student observes
tiny droplets of water forming underneath the lid. The
droplets are clear, not purple.

which property of the water cycle is best shown by step 2 of making the model?
A. clouds tend to form within a certain range of heights above the land or ocean.
B. when ocean water evaporates, the salt is left behind.
C. some of earth's water is trapped in ice caps and glaciers.
D. water vapor mixes thoroughly with other gases of the atmosphere.

Answer 1

The addition of purple food dye in step 2 best demonstrates the property of the water cycle where ocean water leaves behind salts upon evaporation, analogous to the clear droplets formed without dye after condensation.

Step-by-step explanation:

The best representation of the property of the water cycle demonstrated by step 2 of the experiment, where purple food dye is added to water, is Option B - when ocean water evaporates, the salt is left behind. This step simulates the real-world process where as water evaporates, it leaves behind any dissolved substances, such as salts in the ocean.

The clear droplets observed by the student under the lid after the evaporation and condensation process signify that the water that turns into vapor and re-condenses does not carry the impurities or coloring that was present in the original liquid phase.