Question

The atomic number of silicon is 14. Its ground state electron configuration is

• A. $1s^2 2s^2 2p^2 2s^4$
• B. $1s^2 2s^2 2p^6 3s^1 3p^3$
• C. $1s^2 2s^2 2P^2 2P^8 3s^2$
• D. $1s^2 2s^2 2p^6 3s^2 3p^2$

Answer 1

The Correct Option is D

 To determine the ground state electron configuration of an element, we need to arrange the electrons in the available atomic orbitals in order of increasing energy, starting from the lowest. Silicon has an atomic number of 14, meaning it has 14 electrons. Let's distribute these electrons according to the Aufbau principle, which states that electrons occupy the lowest energy orbital available:

1. The first two electrons fill the \(1s\) orbital: \(1s^2\).
2. The next two electrons fill the \(2s\) orbital: \(2s^2\).
3. Six electrons fill the \(2p\) orbital: \(2p^6\).
4. Two electrons fill the \(3s\) orbital: \(3s^2\).
5. The remaining two electrons go into the \(3p\) orbital: \(3p^2\).

Thus, the full electron configuration for silicon is \(1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^2\). This matches the given option:

$1s^2 2s^2 2p^6 3s^2 3p^2$

To confirm, let's compare with the other options:

$1s^2 2s^2 2p^2 2s^4$

$1s^2 2s^2 2p^6 3s^1 3p^3$

$1s^2 2s^2 2P^2 2P^8 3s^2$

These incorrect configurations either misuse orbital labels (e.g., repeated orbitals or incorrect notation) or distribute electrons incorrectly.

Conclusion: The correct ground state electron configuration for silicon, with atomic number 14, is \(1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^2\), which is option

$1s^2 2s^2 2p^6 3s^2 3p^2$

.