Question

What happens to a solid when thermal energy is added?

Answer 1

This happens at the boiling temperature of every substance that can vaporize. At the boiling temperature, adding heat energy converts the liquid into a gas WITHOUT RAISING THE TEMPERATURE.The same thing happens when a solid changes into liquid. For instance, ice and water can exist together at the melting temperature.

Answer 2

First, it depends on the solid, solids melt at different temperatures, but to answer your question, we would say this:

When a solid is heated with thermal energy, the particles in the solid start to vibrate rapidly until the particles cannot hold each other together anymore, then they break apart into a liquid.

Hope I helped.