Question

why alkali metals are colourless as well as diamagnetic

Answer 1

Answer:

Due to this all the remaining electron are paired in alkali metal ion so it is diamagnetic. All the orbital of alkali metal ion is full filled that is why it is highly stable so the electronic Transition cant take place easily hence the ions are colourless.

Answer 2

Answer:

All the elements of group 1 form unipositive ions by loss of one valence electron. So they do not have any unpaired electrons in the ions. Group 2 elements also do not have any unpaired electrons in their divalent ions.nHence their compounds are colourless and diamagnetic.