The total number of electrons that can be accommodated in all the orbitals having principal quantum number $n = 2$ and azimuthal quantum number $l = 1$ is

To which block does an element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$ belong in the periodic table?

List the quantum numbers ($l$ and $m_{l}$) for an electron in a $3d$ orbital.

The configuration $1s^2 2s^2 2p^5 3s^1$ shows

Which of the following rules or principles states that "No two electrons in an atom can have the same set of four quantum numbers"?

If the electronic configuration of a nitrogen atom were $1s^7$,its energy would be lower than the ground state configuration $1s^2 2s^2 2p^3$ because the electrons would be closer to the nucleus. However,the configuration $1s^7$ is not observed. Which of the following principles is violated?