Final answer:
Nitrogen has an electron configuration of 1s² 2s² 2p³, with five valence electrons. It needs three more electrons to satisfy the octet rule.
Step-by-step explanation:
The electron configuration of nitrogen is 1s² 2s² 2p³, which means nitrogen has five electrons in its outer shell (2s and 2p orbitals combined).
To satisfy the octet rule, nitrogen needs three more electrons to complete its valence shell, as eight electrons in the outer shell are required for stability, resembling the electron configuration of the noble gases. Therefore, the answer is B. 3.