Upon going away to college, my former brother-in-law received a hand mixer from his mother because of his fondness for mashed potatoes. Later that semester, she asked him how the mixer was working for him. “Not very good,” Terry said, “the potatoes keep flying all over the kitchen.” 

After a perplexed pause, his mother asked, “Terry, did you cook the potatoes first?” 

To which a surprised Terry responded, “You have to cook the potatoes first?” 

One Liner
What do you do with a sick chemist?
If you can’t helium and if you can curium, then you might as well barium!