The atomic number represents the number of protons present in the nucleus of a certain atom. For a hydrogen atom, which has 1 proton, 1 electron, and 0 neutrons, the atomic number of hydrogen would be 1. The atomic number is the same as the charge number of a nucleus. This number is unique for every element in the periodic table and it distinguishes an element. In a neutral atom, this number is equal to the number of electrons in the atom. Also, the atomic number of an element determines the position of the element in the periodic table which for hydrogen, it is the very first element in the periodic table.