Andy, I've produced an overhead and set of cards for Wednesday. They're rather like the existing worksheet, but more colourfull. (Also, the malignant melonoma I've used to illustrate ulta-violet should be amusingly gruesome.) There are three levels of differentiation, a list of things for the more able groups to discuss, hint cards for the less able, and two extra cards that give away the positions of radio waves and gamma rays for the weaker still. Again, if you have time to comment, I can fix them tonight.