OCR 21C Electromagnetic Radiation Risks

Lesson focused on microwaves. Demo involves heating up a plastic object (I use a chess piece) and a slice of fruit in a microwave. Heat for around 20 seconds, the fruit is quite hot to the touch. I often pretend the chess piece is hot too and 'dare&' students to hold it for 5 seconds, letting them find out that actually it hasn&';t heated up at all. They can usually then work out that water is needed to heat something in a microwave. Students then used comments on the final slide to come up with a 2 minute speech for or against phone masts.