# Question Video: Identifying the Electronic Configuration of an Oxygen Atom Science

An atom of oxygen has 8 protons in its nucleus. Which energy level diagram shows the correct electronic configuration for oxygen? [A] Diagram A [B] Diagram B [C] Diagram C [D] Diagram D [E] Diagram E

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### Video Transcript

An atom of oxygen has eight protons in its nucleus. Which energy level diagram shows the correct electronic configuration for oxygen?

We’ve been given five energy level diagrams labeled from (A) to (E). We need to identify which diagram shows the correct electronic configuration for oxygen. And we are told in the question that oxygen has eight protons. So a neutral atom of oxygen will also have eight electrons. We can immediately eliminate answer choice (E) as the diagram shows that oxygen has 10 electrons, rather than eight.

The other answer choices have the correct number of electrons, but the electrons aren’t necessarily in the correct energy levels. Each energy level has a different maximum number of electrons. K is two, L is eight, M is 18, and N is 32. The maximum number of electrons found in energy level K is two. Thus, answer choices (C) and (D) must be incorrect. Additionally, electrons fill the lowest energy level first, which is K. So two of oxygen’s electrons will be found in energy level K. And the remaining six will be found in the second lowest energy level L. As answer choice (A) has an electronic configuration of 2,6, it is the correct answer. The energy level diagram which shows the correct electronic configuration for oxygen is answer choice (A).