The maximum number of electrons that can have principal quantum number, n=3 and spin quantum number, m_s=- 1 2 , is

Step-by-step solution

When n=3, l=0,1,2 i.e., there are 3 s, 3 p and 3 d orbitals. If all these orbitals are completely occupied as Total 18 electrons, 9 electrons with s=+ 1 2 and 9 with s=- 1 2 . Alternatively In any n th orbit, there can be a maximum of 2 n^2 electrons. Hence, when n=3 , number of maximum electrons =18 . Out of these 18 electrons, 9 can have spin - 1 2 and remaining nine with spin =+ 1 2 .