Year 6 News
Science Reflections
Year 6 visit to the St Saviour’s College Science Laboratory! Week 8 Reversible and Irreversible Changes
When observing the science experiments, I could hear a lot of balloons popping, I couldn’t really smell anything but I could see the smoke from the dry ice as it was really cold and the smoke from the elephant toothpaste which was really hot, so Mr Stokell had to wear gloves.
When we came to the predictions about if they were chemical or physical changes and if they were reversible and irreversible changes, I was able to get all of them right. I think I am a Practitioner and I know more about physical and chemical changes. I know a lot of new information and have a better understanding about it and am now able to identify the difference between reversible and irreversible changes. What I learned was that if you put dry ice in a tube and attach a balloon, the balloon will start to blow up, like it would if you used a helium tank and if you put too much dry ice, eventually it’ll blow up. Another thing that I learned is that dry ice is a physical change because it can turn from a solid into a liquid into a gas and can then transform back into its original form. My favourite science experiment is the elephant toothpaste and it really interested me and I was able to have a lot of fun. I hope to do it again.
Written by Alicia Farkarlun 6W
Out of all the Science experiments we did at the Science lab, elephant toothpaste was my favourite by far! I would love to see it done again. Most of my predictions were correct except for the Sodium Chloride and Silver Nitrate experiment. Now that I’ve gone to that lesson up at the high school, I am much more familiar about physical and chemical changes. I’m also able to identify if experiments are irreversible or reversible. One of the most important safety rules at the lab was to stay a safe distance from the experiments and to not touch anything unless you are told to.
Mrs Doherty showed us a really great example of Atoms. She said that when it’s really, really cold they are all squashed up tightly together, but if you were to heat the object up, the Atoms inside the object will become looser and start to move around more freely causing a solid, liquid or a gas to form. I find it really interesting how the chemicals in liquids, gases and solids mix together to cause a chemical reaction like an explosion or a solid, gas or liquid to form. I’m really glad that we were able to go up to the high school Science lab so that Mr Stockell and Mrs Doherty could explain reversible and irreversible changes to us. I would be excited to go back up to the high school’s Science lab for another lesson about reversible and irreversible changes or something new.
Written by Evangeline Wann
On Thursday morning we had the privilege to go to the high school science lab and experiment real science!
In the first experiment we used copper sulphate and zinc. We saw that the zinc turned to a black colour and bubbles formed upon it. My prediction was correct as I said that It would turn a different colour and become irreversible. In the boiling egg experiment, it became a solid as it was boiling water and began to cook. I predicted that the egg would bubble, but it actually became a solid and the egg white floated down to the bottom. It was a chemical change as well as irreversible. My favourite experiment was the Hydrogen Peroxide and potassium iodide (also known as elephant toothpaste!). When Mr Stokell poured the two chemicals together they got really hot and bubbled over the beaker and steam was coming from it! I predicted that it would be a chemical change and irreversible as you can’t get it back to it’s original form. I also predicted that it would bubble over. I was correct.
The next experiment used a balloon and dry ice. The balloon blew up due to the carbon-dioxide produced by the ice. I predicted that it would be a physical change and irreversible as the dry ice would melt but due to Mrs Doherty’s presentation about atoms , I knew that it could go back to a solid! In the fifth experiment, the materials they used were lead nitrate and potassium. In this experiment, Mr Stokell added both of them into one beaker and it turned into a monkey yellow and became a solid! I predicted that it would be a chemical change and irreversible. I also said it would stay clear, but I was wrong. Since I went to the high school, I have a better understanding of how to recognise what is a reversible and irreversible and what things need to be to deal with experiments.
Written by Gemma Smith
During our time at the college for Science, we got the opportunity to see many different experiments including; Copper Sulphate + zinc; boiling an egg; Elephant Toothpaste; Dry Ice (Balloons etc.) ; Lead Nitrate + Potassium Iodide; Sodium Chloride + Silver Nitrate; Mixture of water and sand. During all of these experiments, we had to predict what would happen and whether we thought it was going to be reversible or irreversible, chemical or physical change. Then, we either got to perform the experiment ourselves, or Mr Stokell would. In all of the experiments, we had to observe whether it was physical/chemical or reversible/irreversible and had to write down our findings. Only one experiment had a peculiar smell but most of them you could just see and hear.
Mrs Doherty explained each experiment in detail and very thoroughly. She showed us the particles, chemicals and atoms by writing the symbols on classmates hands and then showing us how they reacted and what had happened. These explanations really helped me to understand what had happened and whether it was a reversible or irreversible change. Most of my predictions were correct because I guessed correctly at whether it was going to be a reversible/irreversible change and a chemical/physical change. After the lesson at the college, I now have a better understanding of physical/chemical changes and reversible/irreversible changes because we got to visualize it and got a clear explanation. I can identify reversible and irreversible changes easier now and I am feeling great about them now. I learned that when two chemicals are put together they can react and can either separate or make a new substance. I wonder if physical changes can be irreversible, and if chemical changes can be reversible? I noticed that for a lot of the experiments Mr Stokell had to wear protective equipment such as gloves, goggles and a lab coat. My favourite experiment would definitely have to be the Elephant Toothpaste experiment: When Hydrogen Peroxide + Potassium Iodide mixed together with dishwashing liquid and food colouring (for decoration) and bubbled out of the test tube. This was my favourite because it had a fascinating reaction and made me wonder.
I really enjoyed our Science lesson at the college and I would like to thank Mrs Doherty and Mr Stokell for an amazing lesson.
Written by Grace Taylor 6W