Final answer:
The maximum number of electrons in a shell can be determined using the formula 2n². For the n = 2 shell, including the 2s and 2p subshells, the maximum number of electrons is 8. Option number C is correct.
Step-by-step explanation:
The maximum number of electrons that can occupy a shell can be calculated using the formula 2n², where n is the principal quantum number.
For example, the 2s subshell can hold a maximum of 2 electrons, and the 2p subshell can hold a maximum of 6 electrons. Therefore, the maximum number of electrons in the n = 2 shell, including both the 2s and 2p subshells, is 8.