Air Force Officer Qualifying Practice Test 2026 – Comprehensive Exam Prep

The atomic number of an element is a fundamental characteristic that defines the element itself. In the case of carbon, the atomic number is 6, which directly indicates the number of protons found in the nucleus of a carbon atom. Since protons determine both the identity of the element and contribute positively to the atomic mass, knowing that carbon has an atomic number of 6 means it has exactly 6 protons. This is a key aspect of atomic theory and helps in understanding the structure and classification of elements in the periodic table.

Other options do not reflect the correct relationship between atomic number and the quantity of protons for carbon, as they present either too few or too many protons.