Question

Lithium Sodium and potassium elements where put in one group on the basis of their similar properties what are those similar properties

Answer 1

Lithium, pottadsium and sofium comes in the same elctronic configuration, for lithium, 1s2 2s1, for sodium, 1s2,2s2,2p6,3p1, potassium, 1s2,2s2,2p6,3s2,3p6,4s1, u can notice that the last 2 orbitals in all these atoms have a common ns2 np1 configuration, so they r somehow similar