Answer:
3rd principal energy level
Explanation:
Principle energy that explains the energy of the electrons and positions of electrons of a particular atom. There are four energy levels fist to fourth that are made of sublevels and that is made up of s, p, d and f orbitals.
First principal energy level - 2
Second principal energy level - 8
Third principal energy level - 18
Fourth principal energy level - 32
3rd energy level has 9 orbitals, which has 18 electrons
2 in the s orbital,
6 in the three p orbitals, and
10 in the five d orbitals.
So, here there are only 8 electrons in the third principal energy level.