What does the atomic number represent in an atom?

The atomic number is a fundamental property of an element that directly indicates the number of protons present in the nucleus of an atom. This number is unique to each element and determines the identity of the element. For example, hydrogen has an atomic number of 1, meaning it has one proton, and carbon has an atomic number of 6, indicating it has six protons.

The atomic number also indirectly informs us about the number of electrons in a neutral atom, as the number of protons equals the number of electrons when the atom is uncharged. However, it is primarily defined by the number of protons. Additionally, the atomic number is not related to the number of neutrons, nor does it represent the mass of the atom, which is determined by the combined number of protons and neutrons in the nucleus. Thus, the atomic number plays a crucial role in identifying elements and understanding their chemical behavior.