Bharath heated a closed vessel full of water. After some time he observed that the water started boiling. Later there was no water in the vessel.
This is a/an
reversible change.
Reversible change refers to changes that can be undone whereas irreversible change refers to the changes that can't be undone.
When water is boiled into steam, it is a reversible change as the steam can be condensed and converted back into water.