Explain how heating a substance affects its internal energy.

Heating a substance increases its internal energy by raising the kinetic energy of its particles. As the temperature increases, the particles move faster, which contributes to a higher total internal energy.

Method lens: First identify the measured quantity, then match the equation or particle idea to the command word. This question asks: Explain how heating a substance affects its internal energy. The correct response is Heating a substance increases its internal energy by raising the kinetic energy of its particles. As the temperature increases, the particles move faster, which contributes to a higher total internal energy., because internal energy combines particle kinetic and potential energy. In Internal energy, the marking point should connect directly to define internal energy as the total kinetic energy and potential energy of all particles in a system. If the question includes values, the working must keep the appropriate unit and operation; if it is an explanation, it must name the relevant particle behaviour or energy change. This item belongs to Internal energy and energy transfers, so avoid answers that switch to a different quantity, confuse heat with temperature, or describe gas pressure without collisions when collisions are the reason. Checkpoint 212 is distinct because it uses this exact question context and the method lens rather than a generic particle-model sentence.