Here's why:
* Temperature and Molecular Motion: Temperature is a measure of the average kinetic energy of the molecules in a substance. Higher temperature means faster-moving molecules.
* States of Matter:
* Solid: Molecules are tightly packed and vibrate in fixed positions.
* Liquid: Molecules have more freedom to move around but are still close together.
* Gas: Molecules are far apart and move freely.
Phase Changes:
* Melting: When a solid is heated, its molecules gain energy and vibrate faster. If enough energy is added, the molecules break free from their fixed positions and the solid melts into a liquid.
* Boiling/Evaporation: When a liquid is heated, its molecules gain even more energy. If enough energy is added, the molecules escape from the liquid's surface and become a gas.
In summary, increased molecular speed (due to increased temperature) can cause a substance to change from a solid to a liquid (melting) or from a liquid to a gas (boiling/evaporation).
