The number of electrons present in all the completely filled subshells having n =4 and s =+1/2 is \ \ \ \ \ . (Given: n = principal quantum number and s = spin quantum number)

Chemistry · Structure of Atom

JEE Main 2024 — 27 January, Shift 1 — Question 79

The number of electrons present in all the completely filled subshells having $\mathrm{n}=4$ and $\mathrm{s}=+\frac{1}{2}$ is $\_\_\_\_\_$ .

(Given: $\mathrm{n}=$ principal quantum number and $\mathrm{s}=$ spin quantum number)

Numerical answer — enter this value.

Subshells for $n=4$ are 4s, 4p, 4d, 4f

Number of orbitals, we have

4s → 1 orbital 4p → 3 orbitals 4d → 5 orbitals 4f → 7 orbitals

Total number of orbitals $= 1+3+5+7=16$

Each filled orbital contributes one electron with spin $+\frac{1}{2}$ .

Total electrons with spin $+\frac{1}{2} = 16$

Answer key and solution verified before publishing.

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.