The boiling of water

Explain the difference between a physical and a chemical transformation!

A chemical transformation turns substances to other substances, a physical transformation does not.

Is ebullition a physical or chemical transformation?

It is a physical transformation.

What do you observe during ebullition?

The temperature doesn't change during the hole process.

Why?.

A substance like water consists of identical molecules. So they have to behave identically, for instance they have to be on the boil at the same temperature!