Nuclear Energy
Nuclear energy explained in an easy to understand way:

Imagine trying to open a tightly sealed jar of pickles; when you finally succeed, there's a sudden release of pressure. Similarly, nuclear energy involves the release of energy when the nuclei of atoms are split (like opening the jar) or combined. Just as the pressure build-up in the jar is released and can knock the lid off with force, the energy stored in atomic nuclei is unleashed when they're split apart or fused together, powering everything from electricity plants to the sun itself.
Practice Version

Nuclear Energy: The energy released when the nuclei of atoms are split or combined. Nuclear energy. It is the powerful energy generated in the core of an atom when tiny particles are split apart or fused together.