Question

1. How many sub-shells are associated with n = 4? 

2. How many electrons will be present in the sub-shells having m_s value of –\(\frac{1}{2}\) for n = 4?

Answer 1

1. For n = 4, l can have values 0, 1, 2, 3. Thus, there are four sub-shells in n = 4 energy level. 

These four sub-shells are 4s, 4p, 4d and 4f. 

2. For n = 4, the number of orbitals = (4)² = 16. 

Each orbital can have one electron with m_s = –\(\frac{1}{2}\) .

Thus, there are 16 electrons in sub-shells having n = 4 and m_s = -\(\frac{1}{2}\)