The nucleus of a hydrogen atom consists of only one proton. Hydrogen is the simplest and lightest element, and its nucleus is made up of only one positively charged particle, the proton. The proton is located at the center of the hydrogen atom, and it is surrounded by one electron, which is negatively charged.
Neutrons, which are neutral particles, are also found in the nuclei of other elements, but not in the hydrogen atom. Hydrogen has only one electron, and it is located in the electron cloud surrounding the nucleus.
So, to summarize, the nucleus of a hydrogen atom consists of only one proton, and it does not contain any neutrons or electrons.