The electronic configuration $1s^2 2s^2 2p_x^1 2p_y^1 2p_z^1$ corresponds to which of the following elements?

The orbital nearest to the nucleus is

In which of the following pairs of orbitals is the probability of finding the electron zero in the $XY$ plane?

Under normal conditions,which of the following electronic configurations is able to form a dipositive ion?

The element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$ is

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.