Year 4 have started off their new Science topic which is Geology, Mixtures and Separation. They started off the lesson discussing what they already knew and what they would like to learn during the unit of learning.
Then they looked at mixtures and what these are. Miss Edwards passed around a jar of sweets and the children discussed what it was they could see in there and how the sweets could be sorted. From the lesson the pupils found that a mixture is when two or more substances are mixed together and can usually be separated back to their original form and a solution is when they can’t be separated back.
The children in Year 4 are really excited about starting their new topic in Science on chemical changes. In this topic we will be looking at what happens when two chemicals react with each other and recognising if this reaction is reversible or irreversible.
In our first science lesson we talked a lot about the safety procedures we need to follow in these lessons. We then watched our first chemical reaction called Green Fire!
Robins have been excited about the results of our science experiment to find out which liquids cause least damage to eggshells (simulating teeth).
Luckily, due to the fantastic weather, we were able to open the jars outside in the fresh air! Some were rather smelly!
The most damaged egg was by vinegar as it had completely taken away the shell. In fact, the egg was bouncy! We thought about how vinegar is used to pickle food which dates back to the Roman times (our current topic). We remebered how strong vinegar is as we found out on our trip, that Romans used to clean their communal “toilet” sponge using vinegar!
The biggest surprise was that sugar free blackcurrant squash had damaged the eggshell. It has grown a further crusty shell around it and the shell was soft in one area.
The egg in coke had a hard shell but had bady discoloured the shell. It smelt very sweet with such a high sugar content.
The egg that had been in orange juice smelt horrendous and was bady dicoloured although the shell was still hard.
The egg in milk had a hard shell and was in good condition. Similarly, was the egg that had been in water.
We used toothpaste and a toothbrush to clean the eggs and found we could remove the discolouring and build up left on the shell which reminded us of how plaque gathers on teeth.
This experiment confirmed what the dentist had explained to us. Liquids with sugar and acid cause the most damage to our teeth. We concluded that as as result of this experiment, we should avoid these drinks and replace them with water or milk.
This afternoon, Robins became scientists and devised an experiment to investigate which liquid would cause the least damage to teeth. They discussed the need for a fair test, deciding only the liquid should change each time, with all other aspects remaining the same (such as length of time, amount of liquid, type of container and size of egg). After writing up their method, prediction, reasons for fair testing and drawing a labelled diagram, they set up the experiment.
In a lidded jar they added a large egg and then either 300ml of water, milk, orange juice, black currant squash, coke or vinegar. These will now be left for ten days when children will remove the eggs to assess the damage to the shells (our substitute for teeth!). The children were very excited and are looking forward to watching the experiment “develop” over the next few days!
This afternoon Robins were visited by Dr Jugraj Hothi from Bells Lane Dental Practice. He explained and presented lots of information to the children which included:
• What is a dentist?
• What happens at the dentists?
• What are teeth for?
• What types of teeth are there?
• What can go wrong with teeth?
• How do you know if you have a cavity?
• What are safe and unsafe snacks?
• How do you prevent decay?
• What is fluoride?
• What are pits and fissure sealants?
• How is tooth decay fixed?
• What are disclosing tablets?
• How do you brush your teeth properly?
Afterwards, he answered a range of questions from the inquisitive Robins! Here are some of them….