# Question Video: Determining the Maximum Number of Electrons That Can Stay in the Third Lowest Energy Level Science

What is the maximum number of electrons that can occupy energy level X shown in the diagram?

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### Video Transcript

What is the maximum number of electrons that can occupy energy level X shown in the diagram?

Energy levels are regions around the nucleus in which electrons move according to their energies. The energy levels each have a different energy. The energy level closest to the nucleus has the lowest energy. And the energy increases as the energy levels get farther from the nucleus.

In addition to having a different energy, each energy level can hold a different maximum number of electrons. For energy levels one through four, we can calculate the maximum number of electrons each can contain using the equation two 𝑛 squared. 𝑛 in this equation represents the energy level.

To answer the question, we need to determine the maximum number of electrons that the energy level marked X can contain. The X energy level is energy level number three. So we can substitute three for 𝑛 in the equation. Three squared is nine, and two times nine is 18. So the maximum number of electrons that can occupy energy level X in the diagram is 18 electrons.