CONTENTS Learn all about air and water including how air pressure works and what materials float Experiment time 12 Float or sink 14 Fun fountains 16 Skinny water 18 Balloon seesaw 20 Rocket balloons 22 The magic of air 24 Blowing tricks 26 Streamlined for speed 28 Fire extinguisher 30 Model diver 5 Notes for helpers 6 All about air 7 All about water 8 Using this book 10 Scientist kit Do candles need oxygen to burn Find out on page 28 32 Glossary and Index Why do boats float Find out on page 13 Does air have weight Find out on page 19
Notes for HELPERS Help and hazards Help needed All of the experiments are suitable for children to conduct but they will need help and supervision with some This is usually because the experiment requires the use of matches to light candles a knife or scissors for cutting or food coloring These experiments are marked with a Help needed symbol Read the instructions together before starting and help to assemble the equipment before supervising the experiment It may be useful to carry out your own risk assessment to avoid any possible hazards before the child begins Check that long hair and any loose clothing are tied back Check that materials such as matches and scissors are put away safely after use Extra experiments Also try You can also help children with the extra experiments in this book or search the Internet for more similar ideas There are hundreds of science experiment websites to choose from www lovemyscience com This website is packed with simple fun experiments for children to enjoy www sciencebob com experiments index php Engaging science experiments with clearly explained instructions will keep kids busy for hours www sciencefun org kidszone experiments You will find lots of entertaining and informative experiments on this colorful interactive website Publisher’s note to educators and parents Our editors have carefully reviewed these websites to ensure that they are suitable for students Many websites change frequently however and we cannot guarantee that a site’s future contents will continue to meet our high standards of quality and educational value Be advised that students should be closely supervised whenever they access the Internet 5
All about AIR You can’t see it but you can’t live without it Air is all around us and it contains the oxygen we need in order to live Air has weight and it is pressing on you all the time although you won’t be aware of it Air pressure Tiny particles in air called molecules are always bumping into each other The more this happens the greater the air pressure The higher up you go the lower the air pressure and the less oxygen there is in the air Atmosphere In the air The air consists of a mixture of gases mainly nitrogen and oxygen and also dust and moisture Air Nitrogen Exosphere 500 800 km Thermosphere 80 500 km Carbon dioxide Oxygen Other gases The atmosphere Our planet is wrapped up in a blanket of air We call this blanket of many layers the atmosphere It stretches hundreds of miles above our heads The atmosphere keeps in heat at night and protects us from the sun’s rays during the day Mesosphere 50 80 km Stratosphere 10 50 km Troposphere 0 10 km 6
All about WATER All life depends on water no animals or plants could survive without it Most of the world’s water is in the oceans and is salty Freshwater with no salt is found in rivers and lakes Three forms of water Water is the only substance that can exist as a solid ice a liquid water and a gas steam at normal temperatures It melts at 32 F and boils at 212 F Water molecules Water is made of two hydrogen atoms and one oxygen atom It has a chemical formula of H20 A water molecule is shaped like the letter V Rain falls filling rivers Clouds form Water is given off by forests The water cycle All the water on Earth is involved in the water cycle Water droplets or vapors rise from lakes rivers and seas to form clouds These droplets join to make bigger drops that eventually fall as rain Much of the rain runs back into the sea The rivers run back to the sea Water evaporates from the sea Floating and sinking When an object is placed in liquid its weight displaces pushes away a volume of the liquid This liquid pushes back on the solid with a force called upthrust If the upthrust is equal to or greater than the object’s weight the solid will float An object will sink until its weight is equal to the upthrust of the water 7
