Question

What is the value of n for L shell?
A) $3$
B) $2$
C) $1$
D) $4$

Answer 1

We need to know that each electron in an atom is described by four different quantum numbers. The first three $\left( {n,l,m} \right)$ specify the particular orbital of interest, and the fourth (ms) specifies how many electrons can occupy that orbital. Diamagnetic means no unpaired electron while paramagnetic means presence of unpaired electron.

Complete answer:
Let us study the four quantum numbers in brief this makes us easy to answer this question:
Principal Quantum Number (n): $n = 1,2,3, \ldots ,\infty$
Specifies the energy of an electron and the size of the orbital All orbitals that have the same value of n are said to be in the same shell (level).
Angular Momentum (Azimuthal) Quantum Number (l): $l = 0,..,n - 1$
Specifies the shape of an orbital with a particular principal quantum number. The secondary quantum number divides the shells into smaller groups of orbitals and subshells.
Magnetic Quantum Number (mi): ${m_l} = - l...,0,..., + l$
Specifies the orientation in space of an orbital of a given energy (n) and shape (l). This number divides the sub shell into individual orbitals which hold the electrons; there are 2l+1 orbitals in each subshell.
Spin Quantum Number (ms): ${m_s} = + \dfrac{1}{2}or - \dfrac{1}{2}$
Specifies the orientation of the spin axis of an electron. An electron can spin in only one of two directions (sometimes called up and down).
So for L shell the value for n is equal to $2$.

Note:
We need to remember that n electron spins; it creates a magnetic field, which can be oriented in one of two directions. For two electrons in the same orbital, the spins must be opposite to each other; the spins are said to be paired. These substances are weakly attracted to magnets and are said to be paramagnetic.