麻豆约拍

Schools are full of people 鈥� which means they鈥檙e also full of germs. Professor Mark Fielder from Kingston University showed Dick and Dom and some willing volunteers three hair-raising demonstrations.

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You will need:

• Your bathroom
• Glitter
• Water, soap and a towel.
• A volunteer
  

First 鈥� ask an adult if they are happy for you to use glitter in the bathroom. Tell them it will improve your personal hygiene! If you get the go-ahead, sprinkle the glitter onto the flush handle or button on the toilet, and also on the inside door handle. Now get your volunteer to go into the bathroom, lock the door, flush the toilet, and let themselves back out WITHOUT WASHING THEIR HANDS.

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Examine their hands 鈥� you鈥檒l see they鈥檙e covered in glitter. If you now shake hands with them, some of it will transfer onto you. In fact glitter will rub off everywhere they touch. This demonstrates the way that germs are transferred from the toilet into the rest of the house and beyond if you don鈥檛 wash your hands.

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Now ask your volunteer to wash their hands, and dry them thoroughly with the towel. You鈥檒l see the glitter is all gone 鈥� So that鈥檚 why you need to wash your hands to remove germs.

When you鈥檝e got a cold, your body produces snot and your nose fills with bogies. These bogies are to block your nose up and prevent other bugs from getting in, and they鈥檙e sticky so that incoming germs can鈥檛 get past. Snot is full of bugs for this reason 鈥� so when you sneeze, they can be jet-propelled around the room. Not hygienic!

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Here鈥檚 a way of visualising what happens when you sneeze. You will need:

• A balloon
• A balloon pump
• A funnel
• Some glitter.
  

Use the funnel to put some glitter inside the balloon. Now use the balloon pump to blow it up (don鈥檛 use your lips to do this, or they鈥檒l get all glittery.) Hold the end of the balloon until you鈥檙e ready to 鈥榮neeze鈥�. The effect will be particularly spectacular if it鈥檚 over dark material 鈥� Dom鈥檚 black jumper worked well!

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Now let go of the balloon 鈥� and look how far the glitter has travelled. If that had been a real sneeze, those particles would be snot droplets, potentially loaded with germs鈥� So keep a tissue in your pocket, and if you feel a sneeze coming on 鈥� use it, and throw the tissue away in a bin. Remember: catch it, bin it, kill it, and stop the infection cycle!

Anyone who says they don鈥檛 pass wind is lying! Trumps 鈥� or 鈥渇latulence鈥� to use the scientific term - are caused by bugs that live in our gut. They digest the food we eat, producing gas as a side-effect. And that gas that needs to get out 鈥�You can get an idea of how this works with some bakers鈥� yeast.

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You will need:

• Bakers鈥� yeast (available from supermarkets and other food shops)
• Sugar (2 teaspsoons)
• Warm water
• An empty drinks bottle
• A deflated balloon

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Mix the sugar into the warm water and add the yeast. This will activate the yeast, and it will start growing. The yeast uses the sugar as a fuel or food to make the energy it needs to grow, and as part of this process a gas called carbon dioxide is produced.

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We can collect this gas by putting a balloon over the neck of the water bottle once all the ingredients are in there (get an adult to help you with this). Make sure there is a nice seal around the neck of the bottle so the balloon does not leak. Then put the bottle in a warm place and watch! Check every five minutes and see the gas starting to form as the yeast uses the sugar as it grows. Be careful though, only let this go on for about 15-20 minutes as otherwise the gas can build up in the bottle and balloon and the balloon might pop off the bottle and make a mess!

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Once your experiment is over take the bottle outside, and with your adult helper, point the bottle away from you and pull the balloon off. You will hear the gas escape and some of the yeast mix might also come out too! Rinse the bottle out with water and recycle it 鈥� but do not put the lid back on in case any of the yeast is still there and might start to build the pressure up again. Now wash your hands.

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What you have seen is the yeast making gas in the bottle as the sugar is used. Similar processes take place in your intestines with bacteria and your food. Gas is created which moves down your intestines and comes out as a trump or flatulence. All perfectly normal and everyone repeat EVERYONE does it! Now you know how