1. What Energy Does

Energy is the ability to do work or cause change. It is not matter, but it affects matter: it can move it, heat it, stretch it, lift it, or make it glow.

Common forms include kinetic, potential, chemical, thermal, electrical, light, and sound energy.

Deep explanation. Energy is the ability to cause change, and it appears in many forms. Chemical energy is stored in fuels, food, and batteries. Electrical energy moves through circuits. Thermal energy is related to particle motion. Light energy travels as electromagnetic waves. Mechanical energy is associated with motion and position.

Energy is useful because it can transfer or transform. When a lamp turns on, chemical energy in a battery may become electrical energy in a circuit, then light and thermal energy in the bulb. When your body moves, chemical energy from food becomes motion and heat.

GED® routine. Ask what is changing. If something starts moving, kinetic energy increased. If something gets warmer, thermal energy increased. If a battery or fuel is used, chemical energy is being transformed.

⚠️ Common misconception: energy is not a material that disappears. It changes form.

💡 Tip: ask, 'What changed?' Energy is what made the change possible.