Question

As fourth energy level contains 32 electrons but fourt period only contains 18 elements. Why?​

Answer 1

Answer:

after the filling of 4s obtital instead of 4p orbitals there starts the filling 3d orbitals this is in the keeping in the fact of that 3d have less energy than 4p ortibals.hence the 4th period consists of 18 elements and not 8 elements.