Among the following,the correct statement$(s)$ for electrons in an atom is(are):
$A$. Uncertainty principle rules out the existence of definite paths for electrons.
$B$. The energy of an electron in $2s$ orbital of an atom is lower than the energy of an electron that is infinitely far away from the nucleus.
$C$. According to Bohr's model,the most negative energy value for an electron is given by $n=1$,which corresponds to the most stable orbit.
$D$. According to Bohr's model,the magnitude of velocity of electrons increases with increase in values of $n$.

The wave function $\psi_{n, l, m_l}$ is a mathematical function whose value depends upon spherical polar coordinates $(r, \theta, \phi)$ of the electron and is characterized by the quantum numbers $n, l$ and $m_l$. Here $r$ is the distance from the nucleus,$\theta$ is the colatitude,and $\phi$ is the azimuth. In the mathematical functions given in the Table,$Z$ is the atomic number and $a_0$ is the Bohr radius.

Column-$I$	Column-$II$	Column-$III$
$I$. $1s$ orbital	$i$. $\psi_{n, l, m_l} \propto (\frac{Z}{a_0})^{3/2} e^{-(Zr/a_0)}$	$P$. (Graph shown)
$II$. $2s$ orbital	$ii$. One radial node	$Q$. Probability density at nucleus $\propto 1/a_0^3$
$III$. $2p_z$ orbital	$iii$. $\psi_{n, l, m_l} \propto (\frac{Z}{a_0})^{5/2} r e^{-(Zr/2a_0)} \cos \theta$	$R$. Probability density is maximum at nucleus
$IV$. $3d_{z^2}$ orbital	$iv$. $xy$-plane is a nodal plane	$S$. Energy needed to excite electron from $n=2$ state to $n=4$ state is $27/32$ times the energy needed to excite electron from $n=2$ state to $n=6$ state

$1$. For the given orbital in Column-$I$,the only $CORRECT$ combination for any hydrogen-like species is:
$[A] (IV)(iv)(R)$ $[B] (II)(ii)(P)$ $[C] (III)(iii)(P)$ $[D] (I)(ii)(S)$
$2$. For $He^{+}$ ion,the only $INCORRECT$ combination is:
$[A] (II)(ii)(Q)$ $[B] (I)(i)(S)$ $[C] (I)(i)(R)$ $[D] (I)(iii)(R)$
$3$. For the hydrogen atom,the only $CORRECT$ combination is:
$[A] (I)(iv)(R)$ $[B] (I)(i)(P)$ $[C] (II)(i)(Q)$ $[D] (I)(i)(S)$

In $H$ atom,an orbit has a diameter of about $16.92 \ \mathring{A}$. What is the maximum number of electrons that can be accommodated in this orbit?

Match the equations given in List-$I$ with their names in List-$II$.

List-$I$	List-$II$
$(1)$ $\Delta x \cdot \Delta p \ge \frac{h}{4\pi}$	$(A)$ De Broglie equation
$(2)$ $mvr \ge \frac{nh}{2\pi}$	$(B)$ Uncertainty principle
$(3)$ $\lambda = \frac{h}{\sqrt{2m(KE)}}$	$(C)$ Frequency equation of $H$-spectrum
$(4)$ $\nu = 3.29 \times 10^{15} \left( \frac{1}{n_i^2} - \frac{1}{n_f^2} \right)$	$(D)$ Angular momentum is quantized

Given below are two statements:
Statement $I$: Rutherford's gold foil experiment cannot explain the line spectrum of hydrogen atom.
Statement $II$: Bohr's model of hydrogen atom contradicts Heisenberg's uncertainty principle.
In the light of the above statements,choose the most appropriate answer from the options given below:

Match the following laws with their correct statements:

Laws	Statements
$(1)$ Hund's Rule	$(A)$ No two electrons in an atom can have the same set of all four quantum numbers.
$(2)$ Aufbau Principle	$(B)$ Half-filled and fully-filled orbitals have greater stability.
$(3)$ Pauli Exclusion Principle	$(C)$ Electrons prefer to remain unpaired in degenerate orbitals first.
$(4)$ Heisenberg's Uncertainty Principle	$(D)$ It is impossible to determine simultaneously the exact position and exact momentum of an electron.
	$(E)$ In the ground state of atoms,orbitals are filled in the order of increasing energy.