Question

which shows the electron configuration for silicon (si)?
ar4s²3d¹⁰4p⁴
ar3d¹⁴s²
ne3s²3p⁴
ne3s²3p²

Explanation:

Step1: Recall Silicon's atomic number

Silicon (Si) has an atomic number of 14. The electron configuration of an atom can be determined by filling orbitals according to the Aufbau principle, Pauli exclusion principle, and Hund's rule. The noble gas before silicon is Neon (Ne, atomic number 10). So we can use the noble gas notation starting with [Ne].

Step2: Determine the remaining electrons

After Neon (10 electrons), silicon has \(14 - 10=4\) more electrons. The electron configuration for these remaining electrons should follow the orbital filling order: \(3s\) is filled first (holds 2 electrons), then \(3p\) (holds the remaining \(4 - 2 = 2\) electrons). So the electron configuration after [Ne] is \(3s^{2}3p^{2}\).

Step3: Evaluate the options

• Option 1: \([Ar]4s^{2}3d^{10}4p^{4}\): Argon (Ar) has atomic number 18, which is more than 14, so this is incorrect.
• Option 2: \([Ar]3d^{1}4s^{2}\): Also starts with Ar (atomic number 18), incorrect.
• Option 3: \([Ne]3s^{2}3p^{4}\): The \(3p\) orbital has 4 electrons here, but we need 2 electrons in \(3p\) (since \(3s\) takes 2 and total remaining is 4), so incorrect.
• Option 4: \([Ne]3s^{2}3p^{2}\): Matches our calculation, as Ne (10 electrons) + \(3s^{2}3p^{2}\) (4 electrons) gives 14 electrons, which is the atomic number of silicon.

Answer:

\([Ne]3s^{2}3p^{2}\) (the fourth option in the list, with the label corresponding to \([Ne]3s^{2}3p^{2}\))