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Week beginning 11.05.20

Rainbow in a glass!

This week for Science I would like you to follow this video demonstration and then have a go at writing up the experiment as a Scientific model (like we did for the lemon experiment - https://www.ranelaghprimary.co.uk/week-beginning-270420-1/)

Rainbow science

If I learnt anything from this experiment it's that you should ALWAYS check the lids of your food colouring!

Safety and Tips

  • The sugar solutions are miscible, or mixable, so the colors will bleed into each other and eventually mix.
  • If you stir the rainbow, what will happen? Because this density column is made with different concentrations of the same chemical (sugar or sucrose), stirring would mix the solution. It would not un-mix like you would see with oil and water.
  • Try to avoid using gel food coloring. It is difficult to mix the gels into the solution.
  • If your sugar won't dissolve, an alternative to adding more water is to microwave the solutions for about 30 seconds at a time until the sugar dissolves. If you heat the water, use care to avoid burns.
  • If you want to make layers you can drink, try substituting unsweetened soft drink mix for the food coloring, or four flavors of a sweetened mix for the sugar plus coloring.
  • Let heated solutions cool before pouring them. You'll avoid burns, plus the liquid will thicken as it cools so the layers won't mix as easily.
  • Use a narrow container rather than a wide one to see the colors the best.
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