Answer:
2p
Explanation:
Sodium has an atomic number of 11, thus, the neutral atom has 11 electrons. The electron configuration is:
Na: 1s² 2s² 2p⁶ 3s¹
To gain stability, it loses an electron from its outer shell to form the cation Na⁺. Its electron configuration is:
Na⁺: 1s² 2s² 2p⁶
If it were to lose a second electron to form a Na²⁺ cation, the electron should be lost from the 2p orbital subshell and its electron configuration would be:
Na²⁺: 1s² 2s² 2p⁵