Question

Instead of the principal quantum number $\left(n\right)$, the azimuthal quantum number $\left(l\right)$ and the magnetic quantum number $\left(m\right)$, a set of new quantum number $S$, $t$ and $u$ were introduced with a similar logic but different values as defined below:
$S=1,2,3\dots \dots$ (all positive integral values)
$t=(S^2-1^2),(S^2-2^2),(S^2-3^2)\dots \dots$ No negative values
$u=-\frac{(t+1)}{2}$ to $\frac{(t+1)}{2}$ in integral steps.
Each orbital can have maximum four electrons. $(S+t)$ rule is defined similar to $(n+l)$ rule.
Now answer the following questions:

The number of subshells present in the third shell is equal to:

• A. 1
• B. 3
• C. 5
• D. 7

Answer 1

The correct option is B 3

For $S=3$, $t$ can have three value i.e. $(3^2-1^2),(3^2-2^2),(3^2-3^2)$.
So, the number of the subshells in the shell becomes equal to the shell number.