The total number of orbitals in an energy level designated by principal quantum number $n$ is equal to

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

Which of the following ions does not have the same electronic configuration as $Ne$?

The correct order of energy of $2s$-orbitals in $H$,$Li$,$Na$ and $K$ is:

Consider the hypothetical situation where the azimuthal quantum number,$l$,takes values $0, 1, 2, \ldots, n+1$,where $n$ is the principal quantum number. Then,the element with atomic number

Which of the following does not follow the Aufbau principle?