The atoms are held together by bonds to make each molecule.
The molecules have some ability to hold onto each other, but
it is much weaker than the proper bonds between
atoms. The molecules don’t need to
have a lot of energy before they can start to move
around. This is why water has a low melting point.
When water boils to the gas state, it is the molecules
that move apart. The atoms still stay bonded together
to make each molecule:
