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)

Verified step by step guidance

1. Identify the atomic number of silicon (Si), which is 14. This means silicon has 14 electrons in its neutral ground state.
2. Recall the order in which electron orbitals are filled according to the Aufbau principle: 1s, 2s, 2p, 3s, 3p, and so on.
3. Fill the orbitals with electrons following the maximum capacity of each orbital: 1s can hold 2 electrons, 2s can hold 2, 2p can hold 6, 3s can hold 2, and 3p can hold 6.
4. Distribute the 14 electrons in order: fill 1s with 2 electrons, 2s with 2 electrons, 2p with 6 electrons, 3s with 2 electrons, and then place the remaining electrons in the 3p orbital.
5. Write the electron configuration using the notation \$1\,s^{2} 2\,s^{2} 2\,p^{6} 3\,s^{2} 3\,p^{x}\(, where \)x$ is the number of electrons left for the 3p orbital after filling the previous orbitals.