When water is heated at 100∘C, we see no rise in temperature in the thermometer.
True
This is true. When water starts to boil at 100∘C, the temperature does not rise in the thermometer. All the heat energy is used by the water particles to overcome the interparticle forces of attraction and to change their state from liquid to gaseous. This energy, also known as the hidden energy is called the latent heat of vapourisation.