This coming week brings the end of our current Science topic - Solids, Liquids and Gases. We have been looking at separating mixtures in class and we carried out an experiment to separate a mixture of kidney beans, sand and salt. The scientific language used during the experiment was solution, dissolve, filter and evaporate. We talked about what we could do to separate paperclips if they were in the mixture. The following video clip is a similar experiment using a mixture of sand, salt and iron shavings. The scientist in the video used heat to aid the evaporation - we left our solutions on the window sill for 3-4 days with the same effect.
Another thing we learnt about was filtration. Coffee dissolves in water but tea leaves don't so why don't we have tea leaves floating in our tea? A solution (mixture of a liquid and a dissolved solid) will pass through a filter but a solid will not. In this case the filter is the tea bag. The tea bag allows the water to pass through, infusing it with the flavour but the tea leaves stay trapped inside. The following video is a simple explanation of how a filter works.
Another thing we learnt about was filtration. Coffee dissolves in water but tea leaves don't so why don't we have tea leaves floating in our tea? A solution (mixture of a liquid and a dissolved solid) will pass through a filter but a solid will not. In this case the filter is the tea bag. The tea bag allows the water to pass through, infusing it with the flavour but the tea leaves stay trapped inside. The following video is a simple explanation of how a filter works.
