Understanding Energy in Chemistry
Energy is simply the ability to do work, and we measure it in joules (J). You encounter different types of energy every day: mechanical (like a ball rolling), chemical (in batteries), electromagnetic (light), nuclear (from atoms), and thermal (heat).
Kinetic energy is the energy of motion calculatedas1/2×mass×velocity2, while potential energy is stored energy that can be released later. Potential energy comes in three main forms: elastic (like a stretched rubber band), chemical (in food and fuels), and gravitational (a book on a shelf).
The Law of Conservation of Energy states that energy cannot be created or destroyed—it only changes form. This means in any system, the total energy flowing in equals the energy flowing out. When heat transfers, it always moves from high temperature (hot) objects to low temperature (cold) objects, never the reverse.
💡 The faster molecules move, the higher their temperature! When something heats up, the rate of heat transfer actually increases—that's why a very hot object cools down quickly at first, then more slowly.