I have been getting ready for my Intro to Modern Physics final. The professor likes to ask a lot of questions like Which of the following neutron reactions proceeds via the electromagnetic force? Or something like this... I have been looking all over the internet and my text book. All I can find is kind of vague guidelines for this. How would I go about figuring it out? I think the answers are Weak, EM, Strong, Weak (Just not completely sure why).