It is not accurate to state that some liquids sink under water. All liquids have different densities, but they do not typically sink under water unless their density is much higher than that of water.

Water has a density of approximately 1 gram per cubic centimeter (g/cm³). Liquids denser than water will settle at the bottom when combined due to gravity. For example, mercury is a liquid metal with a density of approximately 13.6 g/cm³, making it one of the densest liquids at room temperature. When placed in water, mercury will form distinct globules and sink because its density is much higher.

Here are a few examples of liquids denser than water that will sink:

1. Mercury (Hg): Density = 13.6 g/cm³

2. Gallium (Ga): Density = 5.91 g/cm³ (in liquid state)

3. Sodium (Na): Density = 0.97 g/cm³ (in liquid state)

4. Potassium (K): Density = 0.86 g/cm³ (in liquid state)

It's important to note that some liquids, such as oil or alcohol, are less dense than water and will float on top of it rather than sinking. The relative density of liquids determines their behavior when mixed together.