Question

Thermal energy added to a substance during a change of state causes the substance's temperature to do what?

Answer 1

The energy will be used to break the connections between the molecules and change, for example, a solid into a liquid.

When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation). ... When the pressure exerted on a substance increases, it can cause the substance to condense.

Answer 2

thermal energy is used for increasing kinetic energy between molecules and not the temperature during change of state of matter.

This heat is called latent heat meaning hidden heat as its effect ( temperature increase) cannot be seen.