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01/03/12 The Atmosphere

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The atmosphere is the layer of gases around the earth These gases are known as air

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Air Do the percentages of the gases ever change in air?

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Is the atmosphere heavy? Does the atmosphere have mass? Is it heavy? Yes it does Yes its weight is equal to a layer of water 10.36m thick surrounding the entire surface of the earth So why doesn't it crush us?

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Filling balloons Which gas is more dense? CO 2 Oxygen What is density? Density= Mass/Volume Hydrogen peroxide Test tube Balloon 0.2g of Manganese dioxide Hydrogen peroxide + Manganese dioxide Oxygen

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Carbon dioxide balloon Fill the test tube half way with vinegar Put 3-4 teaspoons of baking soda into a balloon Attach the balloon to the test tube and allow the balloon fill up with gas CO 2

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Oxygen Balloon Very carefully add two 5ml droppers of hydrogen peroxide to a test tube Carefully weigh 0.2-0.3g of manganese dioxide and add it to a balloon Attach the balloon to the test tube and allow the manganese dioxide to fall into the test tube leave for about 8-10mins to allow the balloon to fill Manganese dioxide is a catalyst A catalyst is a substance that speeds up a chemical reaction but does not get used up Oxygen Hydrogen peroxide Test tube Balloon 0.2g of Manganese dioxide Hydrogen peroxide + Manganese dioxide Oxygen

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35mm film canisters Tidy away books and put mat down on desk Fill the canister full with vinegar Put a full spoon of baking soda onto a small square of j-cloth Wrap the cloth into a parcel Drop the parcel into the vinegar and very quickly put on the lid and turn canister upside down on table Fill in section A of worksheet based on your observations

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Uses of carbon dioxide Fizzy drinks Fire extinguishers Stage effects

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Animation of oxygen Fill in section B of worksheet based on your observations