In a neutral carbon atom, which has an atomic number of 6, the electron configuration is 1s² 2s² 2p². This means that:
- The inner shell (1s) is complete with 2 electrons.
- The outer shell (2s and 2p) has a total of 4 electrons (2 in the 2s subshell and 2 in the 2p subshell) but is not complete, as it can hold up to 8 electrons (according to the octet rule).
Therefore, the correct option that describes the structure of the electron shells in a neutral carbon atom is:
The inner shell is complete with two electrons. The outer shell is incomplete with four electrons.