Melting Chocolate in the name of Science

Physics Year 12 students are currently learning about quantum physics and the nature of light and electromagnetic radiation. Visible light, red, blue, green etc are all forms of electromagnetic radiation, as are the microwaves found in your microwave oven. The microwave radiation causes the water molecules in your food to vibrate strongly and so heats your food

The experiment:
• Place two blocks of chocolate end to end on a (partially) flat plate in the microwave, making sure it can’t rotate.
• Turn on the power for two or three minutes!
• Every 6.8cm the chocolate is melted strongly.

The spacing between the melted parts enables us to calculate the frequency of the microwave radiation. Brodie’s back-of-the-chocolate-wrapper calculation revealed a frequency of 2.2GigaHertz very close to the vibrational frequency of water of 2.4GigaHz. As with all good science experiments, the experiment will be repeated next week, with a flatter plate, to improve our results.

Note: no chocolate was harmed during this experiment.