Don't try this at home. (Well, all right, go on then)

The point of science is to create explosions, isn't it? So what could be more educational, not to say diverting, than to make a rocket (above)? Except possibly to create lightning or to make your very own volcano (below). It's not rocket science, unless you want it to be
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1 Making a rocket

You need: a bicycle pump and connector, tape, a plastic bottle, a cork trimmed to fit tightly into the bottle, string, petroleum jelly, a plastic drinking straw, a pair of compasses, scissors, a jug of water, and a football inflator.

Tape the straw lengthways against the long side of the bottle and fix it securely with tape. Make a hole in the cork with the compass and push the football inflator into the hole and through the cork. Pour water into the bottle to a depth of about 5cm. Grease the cork with the petroleum jelly and push it into the bottle so that the football inflator just sticks out.

Tie one end of the string on to a tree or a tall post, and thread the string through the bottle. Tie the other end tightly near the ground. The bottle should be at a 45-degree angle and the water should cover the neck of the bottle. Attach the pump to the football inflator. Put the goggles on and start pumping. The rocket should shoot backwards spraying water forward.

Rockets burn fuel; as the fuel turns into a gas it is expelled and the rocket is thrust forwards. Our rocket expels pressurised water which acts like the gas. Rockets are actually glorified fireworks, which were invented by the Chinese 800 years ago using gunpowder as the fuel.

The first liquid-fuelled rocket was invented by Dr Robert H Goddard, an American engineer, in the early 1900s. It was powered by petrol and liquid oxygen and reached a speed of 60mph and a height of 12.5m in 2.5 seconds. The space shuttle uses both solid and liquid fuel.

 

2 Making a volcano

You need: a baking tray full of sand, a plastic bottle, a small bottle, a funnel, baking soda, vinegar, and food colouring.

Put the vinegar and red food colouring into the small bottle. Half fill the plastic bottle with baking soda and put it in the tray full of sand. Pile the sand round it to create a mountain. Pour the vinegar in and watch the lava flow out. (Wash your hands if you get any of this mixture on you.)

You have created a chemical reaction by adding two chemicals together and seeing a new chemical being formed. The soda, (sodium bicarbonate), reacts with the vinegar (acetic acid) to create a gas called carbon dioxide. The gas expands rapidly and pours out of the bottle. You'll get a similar effect if you shake up a bottle of pop and unscrew the lid. Carbon dioxide creates the bubbles in fizzy drinks. Carbonated drinks were invented in the 1700s by British scientist Joseph Priestley. Carbon dioxide is the gas we breathe out. It buffers the Earth's atmosphere by floating in a layer above us. The more carbon dioxide in the atmosphere, the warmer the Earth; that is the principle behind global warming.

 

3 Making lightning

You need: a metal dish, some plasticine, a metal tin lid, a polythene sheet, scissors, and masking tape.

Tape the polythene to a flat surface – use fairly thick polythene or fold it in two. Make a plasticine handle in the middle of the dish. Touching only the plasticine, rub the dish vigorously on the sheet. After a minute the dish should have a strong charge.

Hold the metal lid a few millimetres away. A spark of static electricity will jump from the bowl to the metal. It's best to do this in the dark.

In 1752, American scientist Benjamin Franklin attached a key to a kite by a silk thread and flew it in a thunderstorm. He could see sparks from the key and felt a mild electric shock when he touched it, thus discovering that lightning was a form of static electricity. This, however, is definitely one not to try at home – people have died doing this.

We now know that lightning forms inside thunderclouds. Violent air currents in clouds break water droplets and ice crystals and smash them together again. That creates static electricity, which is released in a single electric charge – the lightning bolt.

The bolt is so hot it makes air expand at supersonic speeds, releasing the sound that we hear as thunder.

 

4 Woodlice survey

The Natural History Museum is running a national woodlice survey. It involves looking for woodlice and recording where you found them (in your garden, on a walk, in the park) and what you found them under (stones, rotting logs) as well as what species you found and how many.

Enter your results and identify the woodlice on the museum website (www.nhm.ac.uk/interactive/woodlice).

In the UK, there are 37 species of woodlice. This project is an introductory step towards biodiversity. It shows just how many species of woodlice live in your area and the places where they are distributed countrywide.

The results of a previous British survey are also on the Web. Children are encouraged to respond to differences in results between the two surveys.

This introduces children to patterns, distribution and scientific procedure and shows that science doesn't have an explanation for everything. It helps children to understand the concept of a species, and taxonomy (the classification of species).

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