To create a model of a carbon atom, Carrie and Phil will need to understand the composition of a carbon atom based on its atomic number and mass number, as well as the arrangement of subatomic particles within the atom.
A carbon atom has an atomic number of 6, which represents the number of protons in its nucleus. It also typically has 6 neutrons, giving it an atomic mass of approximately 12 atomic mass units (since the atomic mass is the sum of protons and neutrons in the nucleus). Moreover, a neutral atom has an equal number of protons and electrons.