Question

In how many elements the last electron will have the following set of quantum numbers, n=3 and l= 1?

• A. 2
• B. 8
• C. 6
• D. 10

Answer 1

The correct option is C 6

For $n=3$ and $l=1=p$

It is 3p-orbital.

Magnetic quantum number $m_l$ have values from -l to +l and total of $2l+1$ values.

For$l=1$, $m_l$ values are:

$m_l=-1,0,1$ for l=1; total $m_l$ values =3= Number of orbitals

Each orbital can occupy maximum of two electron

Number of electrons $=2\times 3=6$

Thus 6 electrons will show same quantum number values of $n=3$ and $l=1$.

Number of elements with last electron in 3p orbitals = 6