In a TLC analysis of this week's reduction reaction using ethyl acetate and hexanes as the mobile phase, would you expect the reactant or the product to have the larger Rf value

that's what i got you can count the number of atoms

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.