Which of the following represents the electronic configuration of an element with atomic number $17$?

Arrange the orbitals of $H$-atom in the increasing order of their energy:
$3p_x, 2s, 4d_{xy}, 3s, 4p_z, 3p_y, 4s$

Which of the following orbitals has two angular nodes?

If the nitrogen atom had electronic configuration $1s^7$,it would have energy lower than that of the normal ground state configuration $1s^2, 2s^2, 2p^3$ because the electrons would be closer to the nucleus. Yet,$1s^7$ is not observed because it violates:

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:

For $n = 5$ and $m = 2$,which of the following statements is incorrect?