Vídeo de Hydrogen atom. Diagram of an atom of the element hydrogen, pulling back from the central nucleus to reveal its surrounding electron orbital.

Hydrogen is the first element, and has one proton (red) in its nucleus. Hydrogen has one electron, which occupies the lowest energy 1s orbital (green sphere). For clarity, a solid line shows the path of the electron. In reality, the electron can be found anywhere, and the shape of the orbital is based only on where it is most likely to be found