Exploring Convection

Today in science lesson, we explored convection in liquids and gases. Convection is when hot substances rise and cold substances fall/sink to the bottom. To explore this topic we did a few different experiments using food colouring,tea bags,ice,water and matches.

For our first experiment we used an empty tea bag and stood it upright and we then lit it with a match. The result to this was very interesting, as the flame burned the tea bag to the bottom and then the ashes of it floated in the air. This was an example of convection because once the tea bag heated up, it rose and the cool air then fell/sunk.

Our next experiment included using a container of warm water with red food colouring (to symbolise hot) and ice cubes which had blue food colouring (to symbolise cold). We then added the ice cubes to the water and the heat of the water caused the cold iece cubes colouring to sink/fall. This experiment demomstrated convection because once the cold substance was added it almost immediatly sunk and the hot subtance rose.

This science lesson was very entertaining and enjoyable for all of us and we can’t wait for the next one!

By Josie and Beth

Photos taken by Anna

The effect of temperature on gasses

In this science lesson, we learned all about the effect of temperature on gasses. We did an experiment in which we put a balloon on the lid of a bottle and found that putting the bottle in hot water made it inflate and putting it in freezing cold water sucked the balloon in.

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So how did this happen? No, it’s not magic. You see when a gas becomes hot, it expands. This inflates the balloon. And when a gas cools down, it contracts. This causes a vacuum and the balloon is sucked inside the bottle.

 

 

Properties of Gases

Today with Mr Squires we did a science lesson. We all really enjoyed doing an exciting experiment. In previous weeks we learnt about liquids and solids. So this lesson was about gases. We discussed a bit about the properties of a gas. Some of these were; some are invisible, some you can smell, they move freely and gases fill the fully in-closed vessel it is kept in..

We started of the experiment by learning about what we were about to do. We were going to see whether a cup had air in it. Each group had two cups of water and two pieces of tissue paper. There was a few jugs of water on the art tables. We had to push the tissue into the cup so it stayed at the bottom and then first push it into the jug of water upside down making sure that the tissue stayed in the bottom of the cup. We then got the second cup and pushed the tissue in the same way. We then had to pushed the 2nd cup in to the jug the right way.

We all went to our desks to complete a worksheet about our predictions on what will happen. A couple groups at a time we went up to the art tables to actually complete the experiment. My group found that when pushing the cup into the water upside down, less water got soaked up by the tissue than when pushing it down with the opening on top. This was because gases like moving up, so when the cup was upside down it had no where to go because the tissue was there. This meant that the air took up the whole cup and water couldn’t enter. When the opening was a the top, the air escaped which let the water have room to enter. This meant that the tissue got soaked by the water.

Overall, everybody enjoyed this experiment and learning a lot about gases. We can’t wait to have more lessons on gases and ‘What’s the Matter?’

Matthew and Tom working together
Matthew and Tom working together
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Matthew and Tom

 

Changing States Of Matter

Liquid-Solid: Water to Ice

1) The water (liquid) changes to ice (solid).

2) I know this because water flows into to a cup effortlessly and you can also put a solid object into it and make the water level rise. Whereas ice doesn’t flow like water and you can’t put your hand through it (rigid).

3) The water changes into ice due to cold temperature.

4) Ice is useful to us because ice can cool us down and can be put in drinks to make them cool. I think ice is quite useful in household activities.

5) It can actually be reversed by temperature. The ice will melt and turn into a liquid again. This cycle can go on and on.

 

Liquid-Gas: Water to Vapour (Steam)

1) The water (liquid) changes to vapour (gas).

2) I know this because water is wet while gas is usually something you can’t see when you touch.

3) The water changes into vapour because the water is too hot and it evaporates.

4) We usually use this method for ironing and sometimes cooking. It helps us with ironing our clothes and making them look presentable.

5) It can be reversed because the vapour rises up into the sky and becomes part of the clouds. And when the time comes the clouds will get heavy with water (used to be vapour) and then rain down onto the ground. This is a very easy cycle that uses water and steam.

 

Liquid-Gas #2: Petrol to Exhaust Fumes

1) The petrol (liquid) changes to exhaust fumes (gas) which are used for cars, mowers and leaf blowers.

2) I know this because you can put your hand through the exhaust fumes and not feel anything while in water you can feel it.

3) The petrol changes into a gas because it is burning out and being used so it changes into a gas and rises into the air.

4) We use petrol for cars, mowers and leaf blowers (anything that needs petrol for it to work).

5) It cannot change back into a liquid because petrol isn’t like water instead it is a mix of different materials which make it hard to reproduce.

 

Liquid-Solid #2: Watery Ice-cream to Harder Ice-cream

1) The watery mixture of ice cream before it is put in the freezer to a harder ice-cream.

2) I know this because sometimes I look in the box of ice-cream before it’s opened and it is a watery mixture. But after it has been in the fridge it is hard and doesn’t move from the container for a while until it melts a bit.

3) The liquid ice-cream changes into a rigid substance because the temperature cools it and freezes it in a way so it won’t be covered with ice.

4) Loads of people eat ice-cream because it is popular and delicious and we can sometimes use it to cool ourselves down.

5) The harder ice-cream can change back into its watery self by being put out in a hot environment for an extended period of time.

 

Solid-Liquid: Solid Coconut Oil to Liquid Coconut Oil

1) Coconut oil that can be fried in a pan and turned into liquid version of that.

2) I know this because liquid coconut oil flows while solid coconut oil is rigid.

3) The solid coconut oil is put into a fry pan and starts to melt from the heat and turn into a liquid.

4) Coconut oil can be used for cakes, slices, drinks and even face cream! It is very useful around the house.

5) It can turn back into solid due to temperature. It can change back and forth easily.

 

Thank you, hope you like this! I enjoyed doing this and learning about liquids, solids and gases. It was very interesting and I learnt a lot from it!

Ice Melting (Picture Taken by Erin)
Ice Melting (Picture Taken by Erin)

Exploring Viscosity

Yesterday year 6 investigated the viscosity of four different liquids – water, oil, detergent and honey. Viscosity means how much a liquid is resistant to flowing. 20150213-120458.jpg

We all had to devise our own investigations to rank the liquids in order from most viscous to least viscous. More viscous liquids flow slowly, less viscous liquids flow quickly.

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Different groups used different methods to determine the relative viscosity of each liquid. There were lots of great ideas!

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Each group agreed that water was the least viscous and honey was the most viscous, but we had a some disagreements about whether oil or detergent was more viscous. Most groups agreed, however, that these two liquids had a similar viscosity.

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We also looked at what happened when we combined the liquids, to compare the density with viscosity. We found that density and viscosity aren’t necessarily linked.