The atomic number on the periodic table represents the number of protons found in the nucleus of each atom of an element. It is a unique identifier for each element and determines the element's position in the periodic table. The atomic number also equals the number of electrons in a neutral atom, balancing the positive charge of the protons. For example, hydrogen has an atomic number of 1 because each hydrogen atom contains one proton, while oxygen has an atomic number of 8 because it has eight protons.
