"Pairing of electrons in the orbitals belonging to the same subshell does not occur unless each orbital belonging to that subshell has got one electron each." This statement is known as

On what factors does the energy of an atom with more than one electron (multi-electron atom) depend?

Identify the correct statements among the following:
$i. E_{2s}(H) > E_{2s}(Li) < E_{2s}(Na) > E_{2s}(K)$
$ii.$ The maximum number of electrons in the shell with principal quantum number $n$ is equal to $2n^2$.
$iii.$ Extra stability of half-filled subshell is due to smaller exchange energy.
$iv.$ Only two electrons,irrespective of their spin,may exist in the same orbital.

Which statement is not true regarding the $2s$ orbital?

The correct statement about probability density (except at infinite distance from the nucleus) is:

Which of the following plots of radial probability function $4\pi r^2 \Psi ^2$ is incorrectly labelled?