How many electrons can the second and third energy levels hold before they are full?

• A. The second energy level can hold 6 electrons, and the third can hold 10 electrons.
• B. The second energy level can hold 10 electrons, and the third can hold 14 electrons.
• C. The second energy level can hold 2 electrons, and the third can hold 8 electrons.
• D. The second energy level can hold 8 electrons, and the third can hold 18 electrons.

Answer: (D)

Verified step by step guidance

1. Recall that the maximum number of electrons in any energy level (shell) is given by the formula \$2n^2\(, where \)n$ is the principal quantum number (energy level).
2. Identify the principal quantum numbers for the second and third energy levels: for the second energy level, \(n=2\), and for the third energy level, \(n=3\).
3. Calculate the maximum electrons in the second energy level using the formula: \(2 \times (2)^2 = 2 \times 4\).
4. Calculate the maximum electrons in the third energy level using the formula: \(2 \times (3)^2 = 2 \times 9\).
5. Interpret these results to understand that the second energy level can hold 8 electrons and the third energy level can hold 18 electrons before they are full.