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Year 6 science changing materials

Discussion in 'Primary' started by lou2005, Oct 29, 2011.

  1. Try the Hamilton Trust website - it definitely exists on there! They have some ideas you may want to use. I have just finished this unit of work and in our last session we made sherbet. This was to show that an irreversible change occurs when the dry mixture is mixed with water (and more importantly as far the the children were concerned, saliva on their tongue!) The bubbles that are formed are CO2, showing a chemical change which cannot be reversed. Ingredients needed are: icing sugar (1 teasp) bicarbonate of soda (1/2 teasp) and citric acid crystals (1 teasp). You will have to ask for citric acid at your local chemist shop as I've never seen it in the supermarket. I sometimes end this unit also with looking at chemical hazzard symbols. This time round I ran out of time and had to cut it short. Also look at the Northumberland grid for learning at their science self assessment sheets, there is one for this unit which I have just used ( I think they're called Aiming High in Science).
     
  2. tick/star/smileyface

    tick/star/smileyface New commenter

    thank you lou, what a great idea! How did you do the dissolving? in dishes rather than mouths??!! I look forward to doing this. In terms of proving that it was irreversible, what did you do? As I'm sure some of them will suggest evaporation to get it back like salt! THANKS AGAIN!
     
  3. We mixed it up in disposable plastic cups (so I knew they were clean) then transferred one teaspoon of the mixture into a second cup so we could add water to it and watch the reaction. I made the children wash their hands and let them sample the sherbet by putting a little bit on the palm of one hand and dipping their finger into it (yes, sticky hands but hey ho!). We talked about how it felt on the tongue and why it might feel fizzy. We then added a small amount of water and watched it fizz up in the cup. I asked where they thought the bubbles had come from and then explained that when a new material is formed through a chemical reaction, then the change is irreversible. They could see that a chemical reaction had occurred and that a new material had been formed. I would normally follow this up using the BBC science simulation (from Sherston Software) on the interactive whiteboard to observe other reversible and irreversible changes that it would not be possible to replicate in the primary classroom.
     

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