Question

Explain why a piece of glass sinks in water but it floats on mercury

Answer 1

Because mercury is more dense than the iron nail, while water is less dense than the nail. Density is how much a something weighs per volume. ... Oil is less dense that both water and mercury, so it floats on both water and mercury.

Answer 2

If a soild substance A is capable to float upon the the liquid substance B ,then it is obvious that the density of substance B is greater than the substance A.

Similarly,the density of mercury is greater than the glass that's why glass floats on the mercury.

But on the other hand the density of water is lesser than the glass that's why glass cannot float on the water.