Q.72 atomic structure. Why dont i get ans of my question but others get ans around me not only once but 5 6 times

Dear student,

There is basically just one relation that one needs to remember ,.

On the basis of this, and learning a couple of values like energy of orbitals of first four orbitals, the questions from this topic becomes very easy. You just need a little bit of practice on these type of questions and soon these will become handy.

Hope it helps. Regards.