Question

Temperature of a solid doesn't change when its boil

Answer 1

An interesting property of matter is that its temperature will remain constant during a phase change, assuming its surrounding pressure is constant.

In other words, once the temperature of a liquid reaches its boiling point, the temperature will not increase until all the liquid has changed its phase to become a gas. Likewise, once the temperature of a liquid is lowered to its freezing point, the temperature will not decrease until all the liquid has changed its phase to become a solid. A similar effect occurs in the opposite direction.