What does the atomic number represent in an atom?

The atomic number of an atom represents the number of protons present in its nucleus. This fundamental property of the atom is crucial because it defines the element. For example, hydrogen, which has an atomic number of 1, has one proton, while carbon, with an atomic number of 6, has six protons.

The atomic number is also significant in determining the chemical properties of an element. The number of protons in the nucleus influences the arrangement of electrons around the nucleus, which in turn governs how an element interacts with other elements during chemical reactions.

Furthermore, in a neutral atom, the number of protons is equal to the number of electrons, which also relates to the atomic number. However, the atomic number itself specifically refers to protons, making it a pivotal characteristic in identifying each element on the periodic table.