Question

Is \[V{O_2}\]Paramagnetic?

Answer 1

Hint: paramagnetic is made of two words. para’ means unpaired electron and magnetic refers to the magnetic behaviour of the material. Thus, a compound is said to exhibit paramagnetic behaviour if it has an unpaired number of electrons. More the number of unpaired electrons the more is paramagnetic behaviour. Para magnetism is directly proportional to the number of unpaired electrons.

Complete answer:
\[V{O_2}\] is an oxide of vanadium. Vanadium is a d block element having atomic number\[23\]. The electronic configuration of vanadium is

In \[V{O_2}\], the oxidation state of vanadium is\ [ + 4\]. Thus, there will be removal of two electrons from \[4s\] orbital first and then two electrons from \[3d\]subshell. This is because it is a fourth shell orbital and thus present outside than \[3d\] so it is more away from the nucleus. \[4s\]is less attracted by the nucleus thus, it is more easy to remove electrons from it.

There is still one unpaired electron in \[V{O_2}\], thus it exhibits paramagnetic behavior.

Note: While filling of electrons, electrons are first filled in \[4s\] and then \[3d\] due to lower value of \[n + l\]for \[4s\] than \[3d\]. The d block elements usually are coloured because of their paramagnetic properties. These single electrons are free to jump to higher energy levels. When these electrons return to their original energy level or ground state they emit radiation in the visible region. Hence they are coloured. Such excitation is not possible in paired electrons. This is because a large amount of energy has to be spent to overcome the pairing energy and then undergo excitation