Question

what is the value of n+l for 10th electron in the phosphorus

Answer 1

To calculate n+l value for the 10th electron in the phosphorous,  

We first need the electronic configuration of the phosphorous atom,

Electronic configuration of phosphorous:

1s², 2s² 2p⁶, 3s² 3p³.

So the 10th electron is placed in 2p orbital that is having n value equals to 2 and l value equals to 1

So n+l value for the 10th electron will be= 2+1=3