The positively charged particles in an atom's nucleus are called protons. Protons are one of the three subatomic particles that make up atoms, along with neutrons and electrons. The number of protons in an atom determines its element identity and is represented by the atomic number. Each element in the periodic table has a unique atomic number, which corresponds to the number of protons in its nucleus.

Protons have a positive electric charge of +1, which contributes to the overall positive charge of the nucleus. The attraction between the positively charged protons and the negatively charged electrons in an atom is what holds the atom together and prevents it from disintegrating. The number of protons in an atom also determines its chemical properties and behavior.