Explain, in terms of collisions between molecules, why increasing the concentration of O2(g) produces a decrease in the concentration of SO2(g)

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Scientists have developed an explanation of a phenomenon from several verified hypotheses. the explanation has been confirmed through numerous experimental tests.which option best describes this explanation? a. scientific lawb. research questionc. hypothesisd. scientific theory

Which scientists contributed to the determination of how cfcs in clouds in the upper atmosphere could destroy ozone molecules