Question

select the correct answer.
the water cycle is a biogeochemical cycle that is a closed system. which of these sentences describes a viable stage that occurs in the water cycle?
o a. water enters and exits the system boundaries of the cycle.
o b. water can change from solid to liquid at certain points in the cycle.
o c. ice forms anew, adding matter to the cycle.
o d. water vapor condenses, subtracting energy from the cycle.

Explanation:

• A closed system means matter does not enter or exit (so A is wrong).
• In the water cycle, water changes states (solid - liquid - gas). Melting (solid to liquid) is a valid stage (B is correct).
• In a closed system, matter is conserved, so new ice forming (adding matter) is incorrect (C is wrong).
• When water vapor condenses, it releases energy (exothermic), not subtracts energy (D is wrong).

Answer:

B. Water can change from solid to liquid at certain points in the cycle.