Here we have get the group which has the lowest electronegativity in a period among the given groups.
The group 1 elements are more electropositive in nature the removal one electron will have its previous nobel gas configuration.
The electronegativity is not an inherent property of the isolated atom. This concept has been generated for a convenient study of hetero-molecular covalent bond.
The electronegativity is defined as a measure of the tendency of an atom in a molecule to attract the electrons involved in the chemical bond formation.
The group 1 elements are H, Li, Na, K, Rb, Cs and Fr.
The group 3 elements are Sc, Y, La, Ac.
The group 14 elements are C, Si, Ge, Sn, Pb.
The group 17 elements are F, Cl, Br, I, At.
Now the group 1 elements have the valence shell electron ns¹ in the period.
Similarly, group 3, have the valence shell electrons ns²(n-1)d⁰⁻¹⁰(n-2)f⁰⁻¹⁴
group 14 have the valence shell electrons ns²np²
and group 17 have the valence shell electrons ns²np⁵.
Thus the group 1 elements are more electropositive in nature the removal one electron will have its previous nobel gas configuration.