craiyon logo

A 3D model of an atom with a central nucleus of red and blue spheres and glowing blue electron orbits.

A 3D model of an atom with a central nucleus of red and blue spheres and glowing blue electron orbits.

The nucleus is the small, dense center of an atom. It contains protons and neutrons. Electrons are very small, negatively charged particles. They move around the nucleus in regions called electron clouds or energy levels. Mostly empty space in atoms means that even though atoms make up all matter, they are mostly made of space. See more