Touching a cup of hot tea feels hot but touching an ice cube feels cool. Explain based on the motion of molecules.

Question

Accepted Answer

The molecules in hot tea have very high kinetic energy and move rapidly. When our hand touches the hot tea, heat flows from the tea (higher temperature) into our hand (lower temperature), and our hand's molecules gain energy, so we feel hot. In contrast, the molecules in an ice cube have very low kinetic energy and move slowly. When our hand touches the ice, heat flows from our hand (higher temperature) into the ice (lower temperature), so our hand loses thermal energy and we feel cool.