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Primary ICT - Whiteboard Science - 7 Lesson Starts
Primary ICT - Whiteboard Science
Seven Lesson Starts
Support Material for Teachers
Water, Water Everywhere
Year 5 Changing state
Our Robinson Crusoe discovers that he can’t drink seawater. But the Sun is beating down and that gives him an idea. Digging a hole in the sand, he pours in seawater. That makes the sand damp. But the water is still salty.
Now the heat of the Sun becomes helpful. When water is warmed, particles of water vapour escape from the surface. (Even faster if the wind is blowing, but Robinson Crusoe can’t have everything!)
This water vapour condenses – becomes water again – on the surface of the plastic. But because the water evaporated – and not the salt – the water on the plastic is pure. And because the plastic is in a cone, the water runs down it and drips into the cup. The water that collects in the cup is fresh and drinkable.
Closing question:
How is the water made pure, and why is the salt left behind?
Extension:
The water cycle is a world-wide example of this simple principle. Water evaporation from the sea condenses in the clouds and falls as rain. The seawater is salty, but the rainwater is pure. You can demonstrate the water cycle in the classroom. Put a little water in a freezer bag, sealed the top, and tape it from a warm window. Clouds form in the bag and fresh water condenses on it to fall as drops of rain.
The Bear
Year 5 Changing sounds
Our own Indiana Jones is hunting a bear. But the long-suffering Stewart is unable to provide the ideal accompanying music. He tries instrument after instrument to get a low enough pitch. At last the bear emerges from the undergrowth to terrify both of them.
Closing question:
How can you make higher or lower pitched sounds on the guitar?
Extension:
Sounds are made when objects vibrate. The volume of the sound is related to the forces involved – a falling wall makes a lot more noise than a dropped book – but the pitch is related to the size and tension of the object. (Which bars on the chime bar make the lowest sound? – the big ones). So Stewart need larger instrument, with longer, thicker strings. And he finds one!
Many children confused volume and pitch. Experience of different musical instruments will help them to understand the difference. Encourage them to experiment with larger instruments, thicker strings and longer strings to achieve a lower pitch while keeping the volume the same.
Breaking The Chain
Year 4 Habitats and Food Chains
The fox is happy to eat hedgehogs, and hedgehogs to eat caterpillars. The caterpillar in its turn is happy eating green plants. But when the caterpillar leaves for the big city, there are repercussions on the whole food chain. No caterpillars means fewer hedgehogs, and no hedgehogs means a hungry fox. But at least the plants can grow contentedly.
Closing question:
How has the caterpillar leaving affected each of the others in the chain?
Extension:
Most food chains are quite short, and almost all begin with a green plant ‘producer’. The ‘consumers’ include the herbivorous animals, and the carnivorous predators who prey on them. Children can model this, and you can teach them about breaks in the food chain by simply getting them to hold hands or hold on to a length of rope. Take a link away, and the chain is broken.
In reality, there are food webs, rather than chains. Other herbivores will browse on the carrot. Other animals will enjoy a tasty caterpillar. So a food chain is really a line through all that. It represents the flow of energy – from the Sun, through the plant and so to the animals – and is really quite inefficient. Which is why herbivores need to eat a lot of plants, and carnivores need to eat a lot of other animals.
Cross-country
Year 3 Characteristics of materials
Our sleepy hiker imagines a bizarre race between Sarah in the yellow waterproofs, Sir Notalot in the suit of armour and a mummy wrapped in bandages. The metal slows down the knight, but when they reach the water, the mummy suffers from the absorbency of his bandages weighing him down. So Sarah takes the gold.
Closing question:
Why did Sarah’s clothing help her win the race?
Extension:
What is the appropriate clothing for different forms of weather? Some clothing is designed to keep us try, or cool, or warm. Remember to use the word fabric as the word material covers every kind of stuff in science. It is a warm coat actually warm? Or does it just retain the heat of our bodies?
Cool clothes are loose, thin and often light in colour (dark colours tend to absorb the Sun’s heat). ‘Warm’ clothes are not warm of themselves (unless you put your coat on the radiator!) but because they are good insulators, they retain your body heat quite successfully. You warm the clothes and then they warm you.
The Skid Pan
Year 4 Friction
We visit a skid pan, where an expert driver shows us how friction is reduced between the road tyre and the wheel by a thin layer of water. Friction is the grip between two surfaces, which tends to slow things down. Reduce that friction when driving and the result is a skid.
Closing question:
What are the road conditions might cause a loss of friction between the tyres and the road?
Extension:
Friction is a phenomenon between two surfaces, or between a surface and the air or water. High friction surfaces need not be rough; it’s the grip between the particles on the surfaces that matters.
So your hands, although they feel fairly smooth, are so alike that they are high-friction surfaces when rubbed together. The surfaces match each other at te microscopic scale – and they grip. (But try water, hand cream or food oil between them and you will lubricate them and reduce the friction).
Ask children to explore the differences between different shoe soles. Put the shoes on a ramp and see at what angle they begin to slide. Shoes with heavy treads may not grip as well as smooth soles.
Helpful or Harmful?
Year 6 Micro-organisms
Our fully protected researcher opens the door to- a fridge! And inside is food that has rotted because of the action of micro-organisms. But micro-organisms can also be helpful and a baker shows this how living yeast causes bread to rise. A cheese maker explains that even finished cheese still contains living organisms.
Closing question:
What happens to our food waste? What kind of dessert is this? What other uses of micro-organisms can you spot?
Extension:
Without micro-organisms, the Earth would be knee-deep in waste. But we also use micro-organisms to produce a number of natural foods. A popular example is yoghurt, which is produced by the fermentation of milk. But leave a yoghurt too long, and other harmful bacteria will take over, making it inedible.
Yeast is a living thing – a micro-organism that we use in the production of risen, leavened bread and of alcoholic drinks.
Yeast makes bread rise by producing carbon dioxide gas, which makes gas pockets in the bread. Making the dry yeast both wet and warm encourages growth and reproduction – and soon the yeast are busily producing carbon dioxide (and alcohol, though in bread this is lost in the baking process!)
Grow some yeast in the classroom, using warm water and sugar. Make the water is not too hot or too cold or the yeast will either be killed or fail to thrive.
The Archers
Year 4 Moving and growing
Our archer demonstrates how she uses her muscles to pull a longbow. Her muscles work in pairs to move her arm up and down, one muscle lifting her arm and the other lowering it.
Closing question:
Where else have you got pairs of muscles like this in your body? What do they do?
Extension:
Muscles cannot push, they can only pull. They function when they contract and pull on a bone. For this reason, muscles work in pairs. The upper (biceps) muscle lifts your arm upward; and the lower (triceps) muscle brings it down. Because it acts on the elbow end of your forearm, the biceps is horribly inefficient; but the alternative - a muscle that stretched from your shoulder to yor wrist – would be both inconvenient and vulnerable, and would make it hard to put your coat on!
We are familiar with the pulling force of our thigh muscle, which lifts our legs when we run or jump. But can we also push with our thighs? Stand a bathroom scale vertically against the skirting board, and ask children to lie on their backs and press on it with their feet. You can measure the force.
John Stringer
Primary Science Adviser
2008
Note to teachers
This document was not created by Teachers TV but the author has allowed us to publish it here to be used for educational purposes