The identity of an element depend on the number of PROTONS IN THE ATOM.
An atom of an element is made up of three sub particles, which are: electrons, proton and neutron. The proton and the neutron are located inside the nucleus of an atom while the electron is located outside the nucleus, where it orbits around the nucleus. The proton is positively charged and it is the number of proton in an atom that determines the atomic number of an element, which is the identity of that element. For instance, hydrogen has atomic number one while boron has atomic number five. This implies that, hydrogen has one proton and boron has five protons. For a neutral atom, the number of proton and electron are always equal.
