Why is ice solid but floating?

We usually know there are three states of matter, solid, liquid and gaseous, with the atoms in the solid denser than the liquid and the atoms in the liquid thicker than the gas. That is why the solid state of a substance will sink when placed on the liquid of that substance. This happens with most substances but with water, the water is solid, or ice, in some way floating on the surface of the water, why is that?

Why is ice floating on water?

You think that when liquid water starts to freeze, the molecules will stick together more and more tightly, but that's not what actually happened. Water has a special kind of interaction between their molecules that most other substances do not, it is called hydrogen bonding.

Water is made up of one oxygen atom bonded to two hydrogen atoms by covalent bonds and this bond is pulled towards the O atom causing water to be polarized. So water molecules can form H bonds.

Experiments show that when the temperature is> 4 ^° C, the water molecules move strongly, so the H bonds are broken when the water molecules collide with each other due to thermal motion and electrostatic attraction. This means that hydrogen bonds are not strong enough to hold water molecules together.

But when the temperature drops below 4 ^° C, the water molecules slow down enough for hydrogen bonds to connect with each other, so the water molecular structure changes to form a network.

This orderly web structure is less dense than the disordered structure of liquid water. For this reason, the volume of ice increases with the transition from liquid to solid, resulting in a lower density of ice water than the density of liquid water. And you know that if an object is less dense than the liquid containing it, it will float.

So what if the properties of water are the same as most other substances?

A world without floating ice, the ocean floor will be frozen forever. The creatures on the bottom like lobster, crab, seaweed, . will disappear. Forget James Cameron's Oscar because Titanic won't sink. And finally, let's say goodbye to our northern polar cap!