In which of the following transitions is one quantum of energy emitted?

Assertion : $A$ spectral line will be observed for a $2p_x - 2p_y$ transition.
Reason : The energy is released in the form of a wave of light when an electron drops from $2p_x$ to $2p_y$ orbital.

In the transition of an electron in an atom,its kinetic energy changes from $y$ to $y/4$. The change in $P.E.$ will be

Identify the correct statements from the following:
$A$. Heisenberg uncertainty principle is applicable to electrons.
$B$. The size of $2p_x$ orbital is less than the size of $3p_x$ orbital.
$C$. The energy of $2s$ orbital of $H$ atom is equal to the energy of $2s$ orbital of $Li$.
$D$. The electronic configuration of $Cr$ is $[Ar]3d^5 4s^1$.

Which of the following statement$(s)$ is (are) correct?

Match the following items:

$A$. Energy of ground state of $He^+$	$i$. $+6.04 \text{ eV}$
$B$. Potential energy of $I$ orbit of $H$ atom	$ii$. $-27.2 \text{ eV}$
$C$. Kinetic energy of $II$ excited state of $He^+$	$iii$. $8.72 \times 10^{-18} \text{ J}$
$D$. Ionization potential of $He^+$	$iv$. $-54.4 \text{ eV}$