Question

looking at the same nonmetal group on the periodic table, how does the reactivity of an element in period 2 compare to the reactivity of an element in period 4?
the period 2 element would be more reactive because the attractive force of protons is stronger when there are fewer neutrons interfering.
the period 2 element would be more reactive because the attractive force of protons is stronger when electrons are attracted to a closer electron shell.
the period 4 element would be more reactive because the attractive force of protons is stronger when there are more neutrons helping.
the period 4 element would be more reactive because the attractive force of protons is stronger when electrons are attracted to a farther electron shell.

Explanation:

For nonmetals in the same group, reactivity increases up a group (decreases down a group). Period 2 is above period 4, so period 2 nonmetals are more reactive. The reason is effective nuclear charge: electrons in period 2 are in a closer shell to the nucleus, so the attractive force of protons (nuclear charge) on valence electrons is stronger, making it easier to gain electrons (reactivity for nonmetals). The first option's "fewer neutrons interfering" is incorrect (neutrons don't interfere with proton - electron attraction). The third and fourth options say period 4 is more reactive, which is wrong for nonmetals. So the correct reasoning is the second option.

Answer:

The period 2 element would be more reactive because the attractive force of protons is stronger when electrons are attracted to a closer electron shell.