The total number of atomic orbitals in the fourth energy level of an atom is

Identify the element if its expected electronic configuration is $[Ar] 3d^{10} 4s^{2}$.

For a hydrogen atom,the orbital$(s)$ with the lowest energy is/are:
$A$. $4s$
$B$. $3p_x$
$C$. $3d_{x^2-y^2}$
$D$. $3d_{z^2}$
$E$. $4p_z$
Choose the correct answer from the options given below:

Which of the following sets of quantum numbers represents the orbital with the highest energy?

The number of possible spatial orientations of an electron in an atom is given by its

The electrons,identified by quantum numbers $n$ and $l$ as $(i) n = 4, l = 1$,$(ii) n = 4, l = 0$,$(iii) n = 3, l = 2$,$(iv) n = 3, l = 1$,can be placed in order of increasing energy,from the lowest to highest,as: