Question

How many unpaired electrons are there in aluminum?

Answer 1

Hint:To determine the number of paired electrons or number of unpaired electrons present in the atom we should know its atomic number and the electronic configuration. The s orbital can hold maximum two electrons and the p orbital can hold maximum six electrons.

Complete step by step answer:Aluminum is the chemical element present in the periodic table in group 13 and period 3. It is a p-block element. The atomic number of aluminum is 13 which means that the number of protons present in aluminum is 13 and the number of electrons present in aluminum is 13.
The electronic configuration of aluminum is $[Ne]3{s^2}3{p^1}$. The number of valence electrons in aluminum is 3, two electrons are present in s-orbital and one electrons are present in p orbital.
The filling of electrons in the orbitals is based on Hund’s rule which states that the pairing of the electrons is done only when each orbital is singly filled and after that electrons are added. Each orbital can hold two electrons but have opposite spin.
The s orbital can hold maximum two electrons and p orbital can hold maximum 6 electrons. As the s orbital contains two electrons, so the orbital is completely filled. In p orbital only 1 electron is present instead of 6 electrons, so it is incompletely filled. As each orbital can hold a maximum of two electrons, the p orbital of the aluminum contains one unpaired electron.
Therefore, the total number of unpaired electrons present in aluminum is 1.

Note:
The number of electrons tell the magnetic behavior of the atom. As the aluminum contains one unpaired electron in the p orbital it is paramagnetic in nature.