Option (a) Ca, Mn, Co are paramagnetic elements in the fourth period of the periodic table due to unpaired electrons.
A substance's electron configuration can be used to assess if it has magnetic properties: The material is paramagnetic if any of its electrons are unpaired, and it is diamagnetic if all of its electrons are paired.
Materials with hindered electrons that are drawn to magnetic fields are considered to be paramagnetic. In the absence of a magnetic field, they become less magnetic. The magnetic moment of the material and, consequently, the paramagnetism, increase with the number of unpaired electrons.
is the ion with the most paramagnetic behaviour because it has the most unpaired electrons when two electrons are lost.
In this instance, calcium is a paramagnetic element as well. This is an anomaly. Due to the ability of one of calcium's electrons in the S orbital to jump to the D orbital, the element is paramagnetic. Since calcium is in Period 4, its D orbital is unoccupied. D orbitals exist in elements with period 4. Thus, this provides that electron with a destination.
Three electrons are not paired in cobalt. It is hence paramagnetic. Three unpaired electrons are present in the outermost subshell.
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