In an atom,if the $K$-shell has $2$ electrons,the $L$-shell has $8$ electrons,and the $M$-shell has $6$ electrons,what is the total number of electrons in the atom?

Which of these species will have a non-zero magnetic moment?

The outer electronic structure $3s^23p^5$ is possessed by

$p-$ orbitals of an atom in the presence of a magnetic field are

Consider the electronic configuration for neutral atoms:
$(i) \ 1s^22s^22p^63s^1$ $(ii) \ 1s^22s^22p^64s^1$
Which of the following statements is/are false?
$(a)$ Energy is required to change $(i)$ to $(ii)$
$(b)$ $(i)$ represents $Na$ atom
$(c)$ $(i)$ and $(ii)$ represent different elements
$(d)$ More energy is required to remove one electron from $(i)$ than $(ii)$

To which orbital among the following may an electron having zero angular momentum belong?