Question

down the group why does electronegativity decrease and reactivity increase

Answer 1

❄️As you move down a group on the periodic table, the electronegativity of an element  decreases because the increased number of energy levels puts the outer electrons very far away from the pull of the nucleus.

❄️Electronegativity increases as you move from left to right across a period on the periodic table.

Answer 2

As we go down the group the size of atom increases so the atom gain more tendency to lose electron and become electropositive so electronegativity decreases
As the tendency lossing eloctron increases down the group so it can react easily to another atom and form compound Hence reactivity increases down the group.