The atomic number of an element is a fundamental property that identifies and differentiates one element from another. It is denoted by the symbol "Z" and represents the number of protons found in the nucleus of an atom of that element.
Each element on the periodic table has a unique atomic number. For example, hydrogen has an atomic number of 1, helium has an atomic number of 2, carbon has an atomic number of 6, and so on. The atomic number determines the element's position in the periodic table and determines its chemical properties.
In a neutral atom, the atomic number also represents the number of electrons surrounding the nucleus. This is because, in a neutral atom, the number of protons (positive charges) is balanced by the number of electrons (negative charges). The atomic number is essential in defining the identity of an element and understanding its characteristics and behavior in chemical reactions.