Pupils learned more about the weird and wacky world of science when they proved that a liquid can become a solid by hitting it once with a hammer. Prior to the experiment, some girls were very doubtful and stood well back, armed with safety glasses, lab coats and flat shoes, ready to flee the splashing liquid. Others coolly waited, trusting the expertise of teacher Mrs Hermitage.

A mixture of 300g of cornflour and 250ml of water was prepared in a metal bowl. To check that it was a liquid, some girls put their fingers in or shook the bowl. The hammer was then produced. At this point several people ran to the back of the lab!

Year 7 girls watch closely as Sarah hammers the liquid

Year 11 girls are more cautious!

To the amazement of the watching students, when the liquid mixture was hit quite hard with a hammer, it immediately solidified.  Mrs Hermitage explained that the mixture of cornflour and water is a liquid which solidifies on impact. Such liquids are known as dilatant materials or shear thickening fluids. You could even throw it against a wall and watch it shatter. In these materials viscosity increases as the force or shear in them is increased. Therefore the more pressure you apply, the more resistant to deformation they become.

Do try this at home - but only under supervision!