What does the atomic number of an atom represent?

The atomic number of an atom represents the number of protons found in the nucleus of that atom. This fundamental characteristic distinguishes one element from another on the periodic table. For instance, hydrogen has an atomic number of 1, indicating it has one proton, while oxygen has an atomic number of 8, indicating it has eight protons.

The atomic number is critical as it also determines the element's position in the periodic table and its chemical properties. This is because the number of protons influences the electron configuration of the atom, ultimately affecting how it interacts with other atoms.

Also noteworthy is that while atoms are neutral, meaning they have the same number of protons and electrons, the atomic number specifically refers to protons only. Neutrons and isotopes play a role in other aspects of atomic structure, but they are not defined by the atomic number.