GEOLOGY

Detailed explanation-1: -Because there’s more space between the molecules, a volume of hot water has fewer molecules in it and weighs a little bit less than the same volume of cold water. So hot water is less dense than cold water.

Detailed explanation-2: -When water is heated, the water molecules move faster and spread out more. This makes hot water less dense than room temperature water. Since hot water is less dense, it floats on the room temperature water.

Detailed explanation-3: -Cold water has a higher density than warm water. Water gets colder with depth because cold, salty ocean water sinks to the bottom of the ocean basins below the less dense warmer water near the surface.

Detailed explanation-4: -The solid states of other liquids are denser because the molecules pack together tightly when the kinetic energy (temperature) decreases. The hydrogen bonds in water ice are indeed strong, but their orientation causes molecules to push apart, actually lowering density.