What does the atomic number represent?

The atomic number is a fundamental property of an element, and it specifically represents the number of protons present in the nucleus of an atom. Each element on the periodic table is defined by its atomic number, which determines its identity and place in the table. For example, an element with an atomic number of 6 has six protons in its nucleus, which identifies it as carbon.

In neutral atoms, the number of protons is also equal to the number of electrons, which maintains electrical neutrality. However, the atomic number does not directly indicate the number of neutrons or electrons in the outer shell. It solely focuses on the count of protons, making it a key factor in understanding an element's properties and behavior in chemical reactions. Thus, the correct answer accurately defines what the atomic number signifies in atomic structure.