What is the ground-state electron configuration of silicon (Si), atomic number $14$?

• A. $1s^{2}2s^{2}2p^{6}3s^{2}3p^4$
• B. $1s^{2}2s^{2}2p^{6}3s^{1}3p^3$
• C. $1s^{2}2s^{2}2p^{5}3s^{2}3p^3$
• D. $1s^{2}2s^{2}2p^{6}3s^{2}3p^2$

Answer: (D)