Zinc is classified as diamagnetic.
To understand why, we must look at its electron configuration. Zinc has an atomic number of 30, which means it has 30 electrons. Its electron configuration is [Ar] 3d10 4s2, indicating that all the electrons in its outer shell (the 3d and 4s orbitals) are paired.
Diamagnetic materials are characterized by their lack of unpaired electrons. When exposed to a magnetic field, these materials do not have a net magnetic moment and are slightly repelled by the field. This is due to the fact that paired electrons, which constitute the electron configuration of zinc, create a magnetic field that opposes the external field.
In summary, zinc’s completely filled 3d and 4s orbitals mean it does not have any unpaired electrons, which is why it is classified as a diamagnetic substance.