What does the atomic number of an element represent?

The atomic number of an element is defined as the number of protons present in the nucleus of an atom of that element. This number uniquely identifies each element on the periodic table. Each element has a distinct atomic number that determines its chemical properties and its position in the periodic table. For example, hydrogen has an atomic number of 1, meaning it has one proton, while carbon has an atomic number of 6, indicating it has six protons.

Understanding that the atomic number specifically represents the protons in the nucleus is crucial, as it distinguishes one element from another. This foundation helps in grasping related concepts, such as how the atomic structure accommodates neutrons and electrons, but these do not define the atomic number itself.