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Science

Science Week – Van De Graff Generator

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Yesterday we were learning about static electricity. We put our fingertips on a Van De Graff Generator and the hair on our heads and arms started to stick up.

Emily

We had to stand on polystyrene as an insulator otherwise we’d be earthed and would get a small shock. When we touched the Van De Graff Generator, while standing on the polystyrene; we became positively charged! When we stood on the polystyrene, we became a conductor of the static electricity.

The reason our hair sticks up is because the positive charge has nowhere to go and it tries to get away from the other positive charge.

Matthew

To discharge the Van De Graff generator you can touch it with a wand attached to something that’s earthed (like a tap) or you can take your hands off then touch someone else by shaking their hand and giving them a slight shock.

It was  very funny and when people looked at in the mirror  everyone was killing themselves in laughter!!!  After  the Van De Graff generator was turned off, the person who had been using it had to shake the static electricity off and wait for their hair to calm down before they stepped off the polystyrene.

Isla

Thank you for reading this post and we hope you  have learned  something  new!!!

Isla and Abigail 🙂

 

 

Science

Science Week – Viscosity

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One of the topics our class have been focusing on for science week is viscosity.

We learnt that the viscosity of a liquid is how thick or thin it is. If a liquid has high viscosity, it is very thick and moves very slow when you pour it out, but if a liquid has low viscosity it is very thin and runs quickly when you pour it.

Each of us brought in a different liquid and we made a viscosity chain using our knowledge, putting the thickest liquids first and the thinnest ones last. It was sometimes quite  challenging to work out a liquids place in the chain.

For example, a lot of people brought in different types of oil and it was hard to try and work out the viscosity of each one.

We also learnt about non Newtonian and Newtonian liquids. Non Newtonian liquids do not change when force is applied but Newtonian liquids  do change like tomato ketchup when you shake it, paint when you stir it and toothpaste when you mix it.

One good example is cream, when you whisk it, it changes consistency and becomes really thick and no longer takes the shape of its container. It behaves more like a solid.

IDL, Science

Science Week – Making a Lava Lamp

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This week is Science Week, so we decided to make a lava lamp!

We used pure vegetable oil , red food colouring, water and Alka-Seltzer tablets. First, we put in a little bit of water into a big 2 litre bottle then filled the rest of it up with vegetable oil, almost to the top. The water and vegetable oil don’t mix so the vegetable oil sat on top of the water, making two layers.

The next step was to put ten drops of red food colouring into the bottle and wait until they all sank to the bottom and rested in the water.

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Lava Lamp

Now the fun part! We dropped in half an Alka-Seltzer tablet, put the lid on and watched a miracle happen…

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It looked like a volcano had erupted – it was so awesome!!!

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After we took the lid off, it made a fizz noise. It  sounded like when you take the cap off of a bottle off coke.

The reason it made an eruption was because it has a chemical reactions to make the red food colouring burst to the top. The gas in the Alka-Seltzer tablets react to the water and the gas that is produced wants to escape. The little gas bubbles push up through the water and oil, taking some of the food colouring with it and that’s why it sounds like coke when we took the cap off.

We turned the classroom lights off and tried it again, this time with SIX Alka-Seltzer tablets and the mixture went crazy! We put a torch underneath the bottle and it lit up like a real lava lamp.

Then Mrs Falconer left it over night to settle and we when we came back into school the vegetable oil was separated from the water again.

We learned that this is called Molecular Polarity! 🙂