Question

Can electrons be arranged in the L shell without filling electrons in k shell .why?

Answer 1

No

The shells begin from the centre and gradually move outwards. So K shell will always have minimum energy. Similarly, L shell is a little away from nucleus so it will have higher energy than K shell. The outermost shell will have maximum energy. Now it is important to understand the distribution and arrangement of electrons in the atoms of any elements in the different energy levels.
An atom of any element is most stable when it has minimum energy.

An atom will first fill the lowest energy level so as to attain the state of minimum energy. Gradually, the electrons will fill the higher energy levels. Therefore, electrons will first fill K shell, then L shell, M shell, N shell, and so on.