Constantly applied heat by a burner
When a burner is constantly applied to a pot of water, the heat energy is transferred to the water molecules. As the temperature of the water increases, the molecules gain more kinetic energy and move faster.

Boiling water with temperature
As the temperature of the water reaches 100 degrees Celsius, the water molecules start to vaporize and turn into steam. This is the boiling point of water at standard atmospheric pressure.

Temperature of the water during vaporization
During the process of vaporization, the temperature of the water remains constant at 100 degrees Celsius. This is because the heat energy supplied by the burner is being used to break the intermolecular bonds between the water molecules, rather than increasing their kinetic energy.

Explanation
- When the water reaches its boiling point of 100 degrees Celsius, the energy supplied by the burner is used to overcome the intermolecular forces holding the liquid water molecules together.
- As the water molecules break free and turn into steam, the temperature remains constant at 100 degrees Celsius until all the liquid water has been converted into steam.
- Once all the water has vaporized, the temperature of the steam can continue to rise if more heat energy is supplied.
In conclusion, when constantly applying heat by a burner to water, the temperature of the water remains constant at 100 degrees Celsius during the vaporization process until all the liquid water has been converted into steam.