Question

Which property decreases when the element in group 17 are considered in order of increasing atomic number

Answer 1

Electronegativity decreases as you go down a period, aka increasing the atomic number along a specific group, in this case, group 17.

Answer 2

Electromagnetically decreases when the elements are considered in order of increasing atomic number.
In this problem they were asking regarding group 17.
Final answer: Electromagnetically