Question

Which of the following is the correct electron configuration for an oxygen atom?

• A. \( 1s^2 2s^2 2p^4 \)
• B. \( 1s^2 2s^2 2p^6 \)
• C. \( 1s^2 2s^2 2p^5 \)
• D. \( 1s^2 2s^2 2p^3 \)

Hint:

Remember: Electron configuration follows the Aufbau principle, filling lower-energy orbitals first.

Answer 1

The Correct Option is A

Step 1: Determine Oxygen's Electron Count
Oxygen (O) possesses atomic number 8, indicating the presence of 8 electrons.
Step 2: Assign Electrons to Orbitals
Electrons are arranged in orbitals based on the Aufbau principle, filling lower energy levels first: 
- The first energy shell accommodates a maximum of 2 electrons, thus the \( 1s \) orbital is filled: \( 1s^2 \). 
- The second energy shell can hold up to 8 electrons, so the \( 2s \) orbital is filled next: \( 2s^2 \). 
- Subsequently, the \( 2p \) orbital begins to fill. 
With a total of 8 electrons, the remaining 4 electrons are placed in the \( 2p \) orbital: \( 2p^4 \). 
Consequently, the electron configuration for oxygen is: \[ 1s^2 2s^2 2p^4 \] 
Answer:
The electron configuration for an oxygen atom is \( 1s^2 2s^2 2p^4 \). This corresponds to option (1).