Q1-1-1P - Organic Chemistry (Mcmurry)

Question

Give the ground-state electron configuration for each of the following elements: 

(a) Oxygen (b) Nitrogen (c) Sulfur

Step-by-Step Solution

Answer

a) The ground state electronic configuration of oxygen is 1s² 2s² 2p⁴

b) The ground state electronic configuration of nitrogen is 1s² 2s² 2p³ 

c) The ground state electronic configuration of sulfur is 1s² 2s²2p⁶3s²3p⁴

 

Aufbau Principle

The Aufbau principle states that electrons filling takes place in the lowest energy level first. Hund’s rule states that the pairing of electrons in orbitals takes place only after entering each singly occupied electron into the orbital.

a) Oxygen

The oxygen’s  atomic number is 8. So, oxygen has 8 electrons. The filling of electrons takes place by the Aufbau principle and the Hund rule. The energy level diagram is as shown:

Energy level diagram for oxygen

Thus, the ground state electronic configuration of oxygen is $1s^{2}2s^{2}2p^4$

 

b) Nitrogen

Nitrogen’s atomic number is 7. So, nitrogen has 7 electrons. The filling of electrons takes place by the Aufbau principle and Hund’s rule.

Energy level

The energy level diagram for nitrogen is represented as:

Energy level diagram for nitrogen

Thus, the ground state electronic configuration of nitrogen is 1s²2s²2p³

c) Sulfur

The sulfur atomic number is 16. So, sulfur has 16 electrons. The filling of electrons takes place by the Aufbau principle and Hund’s rule.

Electronic configuration

 The energy level diagram for sulfur is represented as:

Energy level diagram for sulfur

Thus, the ground state electronic configuration of sulfur is 1s²2s²2p⁶3s²3p⁴