Page 1
Page 2
Page 3
Page 4
Page 5
Page 6
Page 7
Page 8
Page 9
Page 10
Page 11
Page 12
Page 13
Page 14
Page 15
Page 16
Page 17
Page 18
Page 19
Page 20
Page 21
Page 22
Page 23
Page 24
Page 25
Page 26
Page 27
Page 28
Page 29
Page 30
Page 31
Page 32
Page 33
Page 34
Page 35
Page 36
Page 37
Page 38
Page 39
Page 40
Page 41
Page 42
Page 43
Page 44
Page 45
Page 46
Page 47
Page 48
Page 49
Page 50
Page 51
Page 52
Page 53
Page 54
Page 55
Page 56
Page 57
Page 58
Page 59
Page 60
Page 61
Page 62
Page 63
Page 64
Page 65
Page 66
Page 67
Page 68
Page 69
Page 70
Page 71
Page 72
Page 73
Page 74
Page 75
Page 76
Page 77
Page 78
Page 79
Page 80
Page 81
Page 82
Page 83
Page 84
Electricity is made up of very small blobs called electrons which cannot be seen with our eyes alone. These electrons do not like each others company at all and try to push each other as far away as possible Because of this it can be thought that they are negative towards each other and it is said that they have a negative charge. When too many electrons are trapped together on something the thing that they are stuck on is said to be negatively charged. Things which do not have enough electrons on them are said to be positively charged. Although electrons are exceedingly small it is possible to see them push negatively charged things away and pull positively charged things closer. We will use a balloon to hold the electrons and use their invisible electric force to push and pull some things about. For these fun experiments you will need the following 1 A long balloon 2 Some tissue paper 3 A pair of scissors 4 A kitchen tap 5 An empty drinks can 6 A kitchen or dining table 7 A head of hair - yours will be perfect First blow up the balloon and make a tight knot to hold the air in. Cut up the tissue paper up into small pieces and place these on a table. Rub the balloon through your hair really quickly then slowly bring the balloon up close to the bits of tissue paper. The tissue paper will jump to the balloon off the table and then jump off the balloon as soon as it touches it. This happens because rubbing the balloon makes the electrons from your hair stick to it so it has too many and is negatively charged. The tissue paper has lots of space for the electrons to go to and is positively charged so it is pulled by the electrons on the balloon. Once the tissue paper is on the balloon electrons move onto it and so it then becomes negatively charged and is then quickly pushed away. Now place the empty drinks can on its side on the table. Rub the balloon again through your hair and then without touching the can bring the balloon close to it. The can will start to move towards the balloon. Can you guess why this happens Finally run the kitchen tap so that a very fine stream of water comes out of the tap. Once again rub the balloon through your hair and slowly approach the stream of water halfway between the tap and the sink. Make sure the balloon does not touch the water. What happens to the stream of water Can you think why Electric Balloons Little E insteins C orner hair and slowly approach the The team at the university discovered that mixing the seeds of the pawpaw with kaolinite clay in a nitrogen atmosphere at an elevated temperature created a very effective agent for removing micro-pollutants hydroxyl and carboxyl ions as well as heavy metals from wastewater down to levels below those recommended by the World Health Organisation making the water safe to drink. All the essential materials are readily available and inexpensive giving merging economies a source of clean water that impacts on national health which is an essential factor for economic growth and prosperity. Along similar lines engineers in Malaysia have tackled the problem of removing water contaminated with mercury. This time however instead of the pawpaw seed they resorted to using the pith of... coconuts. By mixing coconuts with activated carbon and using this to clean wastewater contaminated with the cancer-inducing organic and inorganic salts of mercury they came up with a cost-effective means of giving poorer economies access to water quality which to date has been reserved for progressive economies. So it seems that the Bare Necessities and a Lovely Bunch of Coconuts are all one needs if one is to get a clean drink of water anywhere in the world.