The third principal energy level, denoted as n = 3, has a total of three sublevels. These sublevels are ‘3s’, ‘3p’, and ‘3d’.
Each principal energy level can be divided into sublevels that are designated by the letters s, p, d, and f. For the principal energy level n = 3:
- 3s: This sublevel can hold a maximum of 2 electrons.
- 3p: This sublevel can hold a maximum of 6 electrons.
- 3d: This sublevel can hold a maximum of 10 electrons.
Therefore, the total number of sublevels in the third principal energy level n = 3 is three.