Imaginative Teaching Resources & Inspirational Career Ideas from the Chilled Food Industry
Pick up an ice cube with a piece of string
Enjoying a icy chilled drink over the holidays is a great treat but have you tried picking up an ice cube with a piece of string? You can’t, but add a bit of store cupboard science and you can!
Put an icecube in a glass filled to the brim with water – it will bob on the surface. Cut a length of string (wider than the glass) and wet it. Sprinkle some salt on the ice cube, lay the wet string over the icecube and leave for 60 seconds. Pick up the ends of the string and the ice cube will lift up out of the water.
The Why?
The salt lowers the freezing point of water to below 0 degrees C, when we add the salt to the ice cube it melts a thin layer on the ice cube, then the water refreezes around the string allowing you to pick it up. This is why when it is icy weather there is a mix of grit and salt put on the road to reduce ice formation.
Head on over to the Little Passports website for more info.