What does the atomic number of an element represent?

The atomic number of an element represents the number of protons found in the nucleus of an atom of that element. This fundamental property is crucial because it defines the identity of the element; different elements have different atomic numbers. For instance, an atom with one proton is hydrogen, while an atom with six protons is carbon. Since in a neutral atom the number of protons equals the number of electrons, the atomic number also indirectly tells us the number of electrons.

The atomic number is significant in understanding the electronic structure of the atom, its placement in the periodic table, and its chemical properties. Each element’s position in the periodic table is arranged according to increasing atomic number, which reflects the element’s properties and reactions.