Question

Why does the reactivity of non-metals increase moving left to right on the periodic table?

a. The atomic mass of each element's atoms increases.
b. Atoms of elements are closer to filling their valence shell with electrons.
c. Atoms of elements more easily let go of their valence electrons.
d. The valence shells of each element's atoms get larger.

Answer 1

Effective nuclear charge increases across the period from left to right.

I know it not exactly the answer but the nuclear charge happens with electrons and the valence shells of each elements atoms get smaller so I think it is:

B