Question

Is $C{o}^{3+}$ Paramagnetic Or Diamagnetic?

Answer 1

Paramagnetic: A paramagnetic substance is defined as a substance that has at least one unpaired electron.

• A paramagnetic electron is an unpaired electron.
• An atom or ion is said to be paramagnetic even though an orbital has a net spin.
• An atom or ion can have up to ten diamagnetic electrons, but as long as it has one paramagnetic electron, it is considered paramagnetic.

Diamagnetic: Diamagnetic material or elements or substances are those substances that are freely magnetized when placed in a magnetic field.

• According to Lenz's law, diamagnetic materials acquire induced dipoles in the presence of an external magnetic field.
• Diamagnetic material has a weak, negative sensitivity to magnetic fields.
• In diamagnetic materials all electrons are paired so there is no permanent magnetic moment per atom.
• As soon as the external field is removed, they do not retain their magnetic properties.

Cobalt $\left(Co\right)$: Cobalt is a chemical element with atomic number 27.

• Along with nickel, cobalt is found only in chemically combined form in the Earth's crust.
• The electronic configuration of the element cobalt is$\left[Ar\right]4s^{2}3d^7.$
• When a transition metal forms an ion, the ‘s’ electrons are removed before the ‘d’ electrons.
• Therefore, the electronic configuration of the ion $C{o}^{3+}\mathrm{is}\left[Ar\right]3d^6.$
• "$C{o}^{3+}$" is a "d⁶" system with 2 paired electrons and 4 unpaired electrons.

Hence, $C{o}^{3+}$ is paramagnetic.