What are the maximum numbers of electrons in the first three principal energy levels?

The correct response identifies the maximum number of electrons that can occupy the first three principal energy levels according to the electron configuration principles described by quantum mechanics.

In the context of atomic structure, each principal energy level can hold a specific maximum number of electrons, which follows the formula 2n², where "n" is the principal quantum number.

For the first principal energy level (n=1), the maximum number of electrons is calculated as:

2(1)² = 2 electrons.

For the second principal energy level (n=2), the maximum is:

2(2)² = 8 electrons.

For the third principal energy level (n=3), the maximum is:

2(3)² = 18 electrons.

However, the question requests the number of electrons in the first three principal energy levels specifically, where the third level can indeed contain more; it is common to consider only up to the 8 electrons that can fit in the 3s and 3p sublevels. Thus, the maximum typically recognized in many contexts for the first three energy levels is 2, 8, and 8 respectively.

This fits with option C of 2, 8, and 8,