Given a scientific question, generate a correct answer to it.

Input: Consider Input: What is the type of energy that involves movement?

Output: mechanical energy

Input: Consider Input: Exemplified by cesium, which ignites spontaneously in air, pure elements with a high metallic character tend to be very what?

Output: reactive

Input: Consider Input: Similar to the coil on a stove, changes in what reflect an increase in the temperature of a star?
Output: color