The number of unpaired electrons in $1s^2 2s^2 2p^3$ is:

For $s-$orbitals,since $\psi$ (orbital) is independent of angles,the probability $(\psi^2)$ is

The energy required to remove an electron from different subshells of a $H$ atom is given below. What is the order of these energies?

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:

Which of the following sets of quantum numbers is not possible?

The correct electronic configuration of $Ti$ $(Z = 22)$ atom is: