The first three elements of group 1 have the following atomic structure1) Lithium : 3p, 4n ; 2, 1 electrons2) Sodium : 11p, 12n; 2,8,1 electrons3) Potassium : 19p, 20n; 2, 8, 8, 1 electronsWhich of the following features causes them to have similar properties? Each atom has

The chemical reactivity [Properties] of elements depends upon the number of electrons in the valency shell [valency shell electronic configuration]All the alkalimetals have similar valency shell electronic configuration i.e., ns1, therefore they possess similarities in chemical properties.