Final answer:
The electron configuration with 2 electrons in the inner shell, 8 in the second, and 8 in the outer shell corresponds to an element with 18 electrons. This configuration actually describes argon, which is not listed in the answer choices, meaning none of the options (hydrogen, helium, carbon, oxygen) are correct.
Step-by-step explanation:
The electron configuration mentioned, with 2 electrons in the inner energy shell, 8 in the second energy shell, and 8 in the outer energy shell, describes an element with 18 electrons. According to the energy order of orbitals (1s<2s<2p<3s<3p<4s), after filling the 1s, 2s, and 2p orbitals, electrons will fill the 3s and 3p orbitals next. Since the configuration involves two full shells (2 and 8 electrons respectively) and a partly filled or potentially full third shell (8 electrons), we are looking at an element from the 3rd-period which has a complete 3s and 3p subshell. The correct number of electrons (18) matches the noble gas argon, which is not listed among the provided answer choices. Therefore, the options given in the question do not accurately represent the described electron configuration.
Hydrogen, helium, and carbon do not match because they have electron configurations of 1s¹, 1s², and 1s²2s²2p² respectively. Oxygen also does not match the given configuration because it has the electron configuration 1s²2s²2p⁴, totaling only 8 electrons, not 18.