what does the atomic number represent

The atomic number represents the number of protons in the nucleus of an atom of an element. It is denoted by the letter Z and is the characteristic that makes each element unique. For example, every hydrogen atom has an atomic number of 1, indicating that it has one proton in its nucleus. The periodic table is arranged in order of increasing atomic number, and each element is identified by its atomic number. Since atoms are electrically neutral, the number of protons is equal to the number of electrons in an atom. Therefore, the atomic number also determines the number of electrons in an uncharged atom