How many energy sublevels are in the second principal energy level?

There are two energy sublevels in the second principal energy level. These two energy sublevels are 2s and 2p. The energy distribution in an atom is divided into a number of principal energy levels, and the principal energy levels are again divided into four basic energy sublevels.

The sublevels are s (sharp), p (principle), d (diffuse) and f (fundamental). The s sublevel can hold two electrons, and the p sublevel can hold six electrons. Therefore, the second principal energy level can hold a total of eight electrons in the 2s and 2p sublevels. Eight is the maximum number of electrons that the second principal energy level needs to fill its octet.