Have you come up with anything yet? I wouldn't feel right just *telling* you - But think about it and take a guess - do you notice any tubes connected to electricity in common use anywhere?
Well, hang on, let's think about this. What happens when you run electricity through a sealed tube full of gas? Does it *do* anything useful? If you were to notice this phenomenon, what would *you* think of using it for?
What happens when you start throwing charged particles at the atoms in the gas? What else are you learning about in class and the relevant chapter? I can almost guarantee they're related. ;)
Well, I don't know what equipment you have... I can help you figure out where UV and IR waves would be in relation to visible light in the electromagnetic spectrum, though...
Also, think about their wavelengths in relation to the possible wavelengths of visible light!