How many electrons can each energy level hold?

The number of electrons that each energy level can hold depends on the energy level or shell number. The maximum number of electrons that can occupy each energy level can be given by the formula 2n^2, where n is the principal quantum number that represents the energy level.

For example:
- The first energy level (n=1) can hold a maximum of 2 electrons (2 x 1^2 = 2).
- The second energy level (n=2) can hold a maximum of 8 electrons (2 x 2^2 = 8).
- The third energy level (n=3) can hold a maximum of 18 electrons (2 x 3^2 = 18), and so on.

It is important to note that the electron capacity of each energy level may be limited by various factors such as electron configuration and energy sub-levels.