Q25
When water freezes in the polar seas the salts ________
A.
Form a layer on top
B.
Remain in the subsurface water that does not freeze
AnswerC.
Sink to the bottom
D.
Partly freeze and partly sink to the bottom
Answer: Option B
Solution
Answer: Option B
Solution:
When water freezes in the polar seas the salts remain in the subsurface water that does not freeze. Seawater of typical saltiness freezes at about -1.8 °C. The water in contact with the freezing ice is cold and contains some of the salt excluded from the ice, so it is more dense than the warmer water below, and it sinks, mixing with the deeper water. This mixture ends up on the bottom of the ocean.