According to the pauli exclusion principle, when can two electrons occupy the same orbital?

Knowing that a no orbital can accommodate more than two electrons,we can predict the maximum number of electrons in each layer or sub-layer ,It is possible when :

* Only two electrons can be assigned to an s orbital.

* three orbitals in a sub-layer p can accommodate two electrons, this sublayer can accommodate a maximum of six electrons.

* The five d orbitals of a sub-layer can accommodate a total of ten electrons.

hope this helps!

It shows that the experiment is designed properly.