The maximum number of electrons in a subshell of an atom is given by ...........

The four quantum numbers for the valence shell electron or last electron of sodium $(Z = 11)$ are:

Which of the following statements is not correct about the electronic configuration of a gaseous chromium $(Cr)$ atom?

$Ge$ $(Z=32)$ in its ground state electronic configuration has $x$ completely filled orbitals with $m_{l}=0$. The value of $x$ is ..... .

The correct order of decreasing energy for the electrons whose quantum numbers $n$ and $l$ are given below, is
$A$. $n=5, l=2$
$B$. $n=5, l=0$
$C$. $n=4, l=3$
$D$. $n=4, l=1$

The hydrogen-like species $Li^{2+}$ is in a spherically symmetric state $S_1$ with one radial node. Upon absorbing light,the ion undergoes transition to a state $S_2$. The state $S_2$ has one radial node and its energy is equal to the ground state energy of the hydrogen atom.
$1.$ The state $S_1$ is
$(A)$ $1s$ $(B)$ $2s$ $(C)$ $2p$ $(D)$ $3s$
$2.$ Energy of the state $S_1$ in units of the hydrogen atom ground state energy is
$(A)$ $0.75$ $(B)$ $1.50$ $(C)$ $2.25$ $(D)$ $4.50$
$3.$ The orbital angular momentum quantum number of the state $S_2$ is
$(A)$ $0$ $(B)$ $1$ $(C)$ $2$ $(D)$ $3$
Give the answer for questions $1, 2$ and $3.$