The number of atomic orbitals from the following having $5$ radial nodes is $.......$. $7s, 7p, 6s, 8p, 8d$

The atomic number of the element having the maximum number of unpaired electrons (in the ground state) is ........

What is the orbital angular momentum of an electron in a $2s$-orbital?

The plot of $r^2 \Psi^2$ versus $r$ for $2s$ orbital of hydrogen atom exhibits :-

Arrange the following atomic orbitals of multi-electron atoms in order of increasing energy.
$A$. $n=3, l=2, m=+1$
$B$. $n=4, l=0, m=0$
$C$. $n=6, l=1, m=0$
$D$. $n=5, l=1, m=+1$
$E$. $n=2, l=1, m=+1$
Choose the correct answer from the options given below:

In an atom, the order of increasing energy of electrons with quantum numbers $(i)$ $n=4, l=1$, (ii) $n=4, l=0$, (iii) $n=3, l=2$, and (iv) $n=3, l=1$ is: