The azimuthal quantum number for the valence electrons of $Ga^{+}$ ion is $.....$
(Atomic number of $Ga = 31$)

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 of the following shows half-filled configuration?

Which of the following statements is $FALSE$?

What is the difference between the $2s$ orbital of hydrogen and the $2s$ orbital of other multi-electron atoms?

Given below are two statements :
Statement $I$ : $A$ spectral line will be observed for a $2p_x \rightarrow 2p_y$ transition.
Statement $II$ : $2p_x$ and $2p_y$ are degenerate orbitals.
In the light of the above statements,choose the correct answer from the options given below :