Question

The density of ocean water increases when it

Answer 1

The ocean's water's density increases when it gets colder.
The molecules in the water get colder and move less, causing it to densify... As though it were freezing (though we all know the ocean hasn't ever frozen)

Answer 2

Answer: The correct answer is b. gets older.

Explanation: Density is defined as ratio of mass and volume.

Mathematically,

$Density=\frac{Mass}{Volume}$

We know that volume is directly related to temperature.

$Volume \propto Temperature$

When the temperature of the substance increases, particles gets separated and this results in the increase of volume.

When the temperature of the substance decreases, the particles come closer to each other, resulting in the decrease of volume.

From the above relation, we conclude that the temperature is inversely related to density.

$Density=\frac{1}{Temperature}$

As the temperature gets colder, it results in the increase in the density. Hence, the correct option is b.