Which of the following correctly compares the radii of f and f−?

F has a smaller radius than F− due to an additional electron that causes greater repulsion in F−

Explanation:

F is a non-metal in a group of the periodic table called halogens.F reacts by gaining electrons to form a negatively charged ion F- which has an additional electron.Atomic radius is the radius of an atom such an F atom while the ionic radius is the radius of an ion formed when an atom gains or loses electron(s). The atomic radius of F is smaller than the ionic radius of F- due to the presence of an additional electron in F- which increases the repulsion and decreases the attraction by the nucleus.

Compound with sulfer  is bright red