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 unique number is fundamental for identifying an element and differentiates it from others on the periodic table. Every element has a specific atomic number, which corresponds directly to its position in the periodic table. For instance, the atomic number of hydrogen is 1, indicating it has one proton, while carbon has an atomic number of 6, meaning it has six protons.

Additionally, the atomic number also provides insights into the element's electron configuration in a neutral atom, where the number of electrons equals the number of protons. However, the atomic number itself specifically refers only to protons. The total atomic mass, on the other hand, takes into account both protons and neutrons, further emphasizing that the atomic number is solely a count of protons.