# Question #b3a29

##### 1 Answer
Feb 1, 2016

Paramagnetism is when a substance has an electron configuration with at least one unpaired electron.

A common example for a paramagnetic element is iron, atomic number $26$. Its electron configuration is $\left[\text{Ar}\right] 3 {d}^{6} 4 {s}^{2}$.

We should recognize that with $l = 2$ for the $3 d$ orbital, there are ${m}_{l}$ values of $- 2 , - 1 , 0 , + 1 , + 2$, giving $2 \times 5 = \setminus m a t h b f \left(10\right)$ electrons possible within the $3 d$ orbitals.

You only have $6$ in the $3 d$ for iron, so using the Aufbau principle, the Pauli Exclusion Principle, and Hund's rule, four of the orbitals have unpaired electrons.

Therefore, iron is paramagnetic.

As a side note, a diamagnetic compound has no unpaired electrons at all. So, zinc is diamagnetic.