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: Recall the electron configuration for oxygen
Oxygen (O) has an atomic number of 8, meaning it has 8 electrons. 
Step 2: Distribute the electrons in orbitals
The electron configuration follows the Aufbau principle, which fills the lowest energy orbitals first: 
- The first shell can hold up to 2 electrons, so the \( 1s \) orbital is filled first: \( 1s^2 \). 
- The second shell can hold up to 8 electrons, so the \( 2s \) orbital is filled next: \( 2s^2 \). 
- After that, the \( 2p \) orbital starts filling. 
Oxygen has 8 electrons in total, so the next 4 electrons will go into the \( 2p \) orbital: \( 2p^4 \). 
Therefore, the electron configuration of oxygen is: \[ 1s^2 2s^2 2p^4 \] 
Answer:
Therefore, the correct electron configuration for an oxygen atom is \( 1s^2 2s^2 2p^4 \). So, the correct answer is option (1).