Why Does Ice Float On Water? - Science ABC

Water is less dense in its frozen form, ice, than it is in its liquid form. This is because the molecules in ice are further apart than the molecules in liquid water. The molecules in ice are held further apart by the hydrogen bonds between the oxygen and hydrogen atoms.

From giant icebergs to tiny cubes, ice – the frozen form of water – always floats on its liquid form. Isn’t that weird?

We’re not the only ones who think it’s unusual; the entire world finds it rather surprising that a solid should float on its liquid form. Do a quick Google search and you’ll find dozens of pages discussing this queer tendency of ice.

As it turns out, like everything else, there is a scientific reason behind this phenomenon. But first off, let’s be clear about what makes stuff sink or float.

The singular rule of thumb, when it comes to the ability of an object to float in water (or any other liquid), concerns the density of the object in question. Have you ever heard of Archimedes’ Principle?

Archimedes’ Principle states that for an object to float on water, it must displace an equal amount of water. In other words, you can say that the fate of an object in a body of water is decided by Archimedes’ Principle.

It’s common knowledge that solid objects have more density than their liquid counterparts. Chemically, this makes sense too. Molecules are more closely bound with one another in a well-defined manner in a solid, which makes them rigid and gives them more weight. All common substances that we see and observe in daily life follow this basic principle: solid objects are denser and have more weight than liquids.

Given that, why does ice – which is a solid – float on water? Shouldn’t it sink, as a solid, and according to general convention, also have more density?

Recommended Video for you:

Does Water Expand When It Freezes?