The atomic number of an atom represents the number of protons in the nucleus of that atom. It is often denoted by the symbol "Z." The equation to express the relationship between the atomic number, the number of protons, and the number of electrons in a neutral atom is as follows:
Atomic Number (Z) = Number of Protons = Number of Electrons
In a neutral atom, the number of protons (and electrons) is equal to the atomic number. For example, if an atom has an atomic number of 6, it means that it has 6 protons in its nucleus and 6 electrons surrounding the nucleus.