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?

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

Match the items in List-$I$ with the items in List-$II$.

List-$I$	List-$II$
$A$. Nodes	$I$. Three dimensional shape of the orbital
$B$. Subsidiary quantum number	$II$. Significant only for motion of microscopic objects
$C$. White light	$III$. $|\psi|^2$ is zero
$D$. Heisenberg uncertainty principle	$IV$. Spin state of electron
	$V$. Continuous spectrum

The statement that is $NOT$ correct is:

Which of the following statements is $CORRECT$ :
$(I)$ Where orbitals are available in degenerate sets,maximum spin multiplicity is observed.
$(II)$ Where two electrons occupy the same shell,they may have same spins.
$(III)$ All noble gases do not have the same valence shell electronic configuration.

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