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Children ask why a raw onion tastes so different from a cooked onion. One of the children wants the others to eat a raw onion as an experiment. They're not keen because the taste and smell of a raw onion is so strong and the acid vapour emitted from it makes your eyes water. After cooking, these effects disappear and the children are curious to know why.
This clip is from:
First broadcast:
16 May 2007

Classroom Ideas

This clip could be used to introduce the idea of chemical reactions to students. This could encourage students to consider and discuss other chemical reactions they experience every day, such as cooking toast or baking a cake.

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