Science Experiments Ideas

1. Place a pair of binoculars in an open window in the direct path of the suns rays. Stand a mirror in front of one eyepiece so that it throws an image of the sun on to the opposite wall of the room. Adjust the mirror until the image is sharp, and darken the room. You would risk damaging your eyes if you looked directly at the sun through binoculars, but you can view the bright disc on the wall as large and clear as in the movies. Clouds and birds p .....

Sun clock

2. Place a flowerpot with a long stick fixed into the hole at the bottom in a spot, which is sunny, all day. The sticks shadow moves along the rim of the pot as the sun moves. Each hour by the clock mark the position of the shadow on the pot. If the sun is shining, you can read off the time. Because of the rotation of the earth the sun apparently passes over us in a semi circle. In the morning and evening its shadow strikes the pot superficially, w .....

Watch as a compass

3. Hold a watch horizontally, with the hour hand pointing directly to the sun. If you halve the distance between the hour hand and the 12 with a match, the end of the match points directly to the south. In 24 hours the sun .....

World time clock

4. The earth rotates in 24 hours from west to east once on its axis. In this time the sun shines on all regions of the globe one after the other and determines their time of day. To enable a practical calculation of the time, the earth is divided into 24 time zones, which are very simply shown on the map below. Since in a few areas, which belong together, a uniform time has been introduced, the boundaries of the time zones sometimes run along state .....

Maze

5. Plant a sprouting potato in moist soil in a pot. Place it in the corner of a shoebox and cut a hole in the opposite side. Inside stick two partitions, so that a small gap is left. Close the box and place it in a window. After a couple of days the shoot has found its way through the dark maze to the light. Plants have light sensitive cells, which guide the direction of growth. Even the minimum amount of light entering the box causes the shoot to .....

The sun brings life

6. Fill a large glass jar with fresh water and place in it several shoots of water weed. Place the jar in sunlight, and at once small gas bubbles will rise in the water. Invert a funnel over the plants and over it a water filled glass tube. The gas, which is given off by the plants slowly, fills the tube. Plants use sunlight. With its help, in the presence of chlorophyll, they make their building material, starch, from water and carbon dioxide, an .....

Automatic watering

7. Fill a bottle with water and place it upside down and half buried in soil in a flower box. An air bubble rises up in the bottle from time to time, showing that the plants are using the water. The water reservoir is enough for several days, depending on the number of plants and the weather. Water only flows from the bottle until the soil round it is soaked. It starts to flow again only when the plants have drawn so much water from the soil that i .....

Secret path

8. Dissolve a teaspoonful of salt in a glass of water and cover it tightly with parchment paper. Place the glass upside down in a dish containing water strongly coloured with vegetable dye. Although the parchment paper has no visible holes; the water in the glass is soon evenly coloured. The tiny particles of water and dye pass through the invisible pores in the parchment paper. We call such an exchange of liquids through a permeable membrane, osmos .....

Rising sap

9. Make a deep hole in a carrot and fill it with water in which you have dissolved plenty of sugar. Close the opening firmly with a bored cork, and push a plastic straw through the hole. Mop up any overflowing sugar solution, and seal the joints with melted candle wax. Put the carrot into water and watch after some time the sugar solution rises into the straw. The water particles can enter the carrot through the cell walls, but the larger sugar par .....

Ghostly noise

10. Fill a wineglass to overflowing with dried peas, pour in water up to the brim, and place the glass on a metal lid. The pea heap becomes slowly higher and then a clatter of falling peas begins, which goes on for hours. This is again an osmotic process. Water penetrates into the pea cells through the skin and dissolves the nutrients in them. The pressure thus formed makes the peas swell. In the same way the water necessary for life penetrates the .....

Rain in a jar

11. Place a green twig in a glass of water in sunlight. Pour a layer of oil on to the surface of the water and invert a large jar over the lot. After a short time, drops of water collect on the walls of the jar. Since the oil is impermeable, the water must come from the leaves. In fact the water which the plant absorbs is given off into the air through tiny pores in the epidermis of the leaf. Air saturated with moisture and warmed by the sun deposit .....

Zig zag growth

12. Lay pre germinated seeds on a sheet of blotting paper between two panes of glass, pull rubber bands around the panes and place in a water container in a window. Turn the glass panes with the shoots onto a different edge every two days. The roots always grow downwards and the stem grows upwards. Plants have characteristic tendencies. Their roots strive towards the middle of the earth and the shoots go in the opposite direction. On slopes the root .....

Leaf skeleton

13. Place a leaf on blotting paper and tap it carefully with a clothes brush, without pressing too hard or moving sideways. The leaf is perforated until only the skeleton remains, and you can see the fine network of ribs and veins. The juicy cell tissue is driven out by the bristles and sucked up by the blotting paper. The ribs and veins consist of the firmer and slightly lignified framework and resist the brush. .....

Two Coloured Flower

14. Dilute red and green fountain pen inks with water and fill two glass tubes each with one colour. Split the stem of a flower with white petals, e.g. a dahlia, rose or carnation, and place one end in each tube. The fine veins of the plant soon become coloured, and after several hours the flower is half red and half blue. The coloured liquid rises through the hair fine channels by which, the water and food are transported. The dye is stored in the .....

Colour magic

15. Cut a red cabbage leaf into small pieces and soak in a cup of boiling water. After half an hour pour the violet coloured cabbage water into a glass. You can now use it for crazy colour magic. Place three glasses on the table, all apparently containing pure water. In fact only the first glass contains water, in the second is white vinegar and in the third water mixed with bicarbonate of soda. When you pour a little cabbage water into each glass, .....

Violet becomes red

16. If you ever come across an anthill in the woods, you can there and then do a small chemical experiment. Hold a violet flower, e.g. a bluebell, firmly over the ants. The insects feel threatened and spray a sharp smelling liquid over the flower. The places hit turn red. The ants make a corrosive protective liquid in their hindquarters. You notice it if an ant nips you, though it is generally quite harmless. Since the flower turns red where the dro .....

Invisible ink

17. If you ever want to write a secret message on paper, simply use vinegar, lemon, or onion juice, as the invisible ink. Write with it as usual on white writing paper. After it dries the writing is invisible. The person who receives the letter must know that the paper has to be held over a candle flame the writing turns brown and is clearly visible. Vinegar, and lemon or onion juice, cause a chemical change in the paper to a sub stance similar to .....

Bleached rose

18. A piece of sulphur is ignited in a jam jar. Since a pungent vapour is produced, you should do the experiment out of doors. Hold a red rose in the jar. The colour of the flower becomes visibly paler until it is white. When sulphur is burned, sulphur dioxide is formed. As well as its germicidal action in sterilisation, the gas has a bleaching effect, and the dye of the flower is destroyed by it. Sulphur dioxide also destroys the chlorophyll of plan .....

Transfer pictures

19. Photos and drawings from newspapers can be copied easily. Mix two spoonfuls of water one spoonful of turpentine and one spoonful of liquid detergent and dab this liquid with a sponge on the newspaper page. Lay a piece of writing paper on top, and after vigorous rubbing with a spoon the picture is clearly transferred to the paper. Turpentine and liquid detergent when mixed form an emulsion, which penetrates between the dye and oil particles of t .....

Sugar fire

20. Place a piece of cube sugar on a tin lid and try to set it alight. You will not succeed. However, if you dab a corner of the cube with a trace of cigarette ash and hold a burning match there, the sugar begins to burn with a blue flame until it is completely gone. Cigarette ash and sugar cannot be separately ignited, but the ash initiates the combustion of the sugar. We call a substance, which brings about a chemical reaction, without itself bei .....

Jet of flame

21. Light a candle, let it burn for a while, and blow it out again. White smoke rises from the wick. If you hold a burning match in the smoke, a jet of flame shoots down to the wick, and it re lights.After the flame is blown out the stearin is still so hot that it continues to evaporate and produce a vapour. But as this is combustible, it can be re lighted at once by a naked flame. The experiment shows that solid substances first become gaseous at th .....

Gas pipe

22. Roll a thin piece of tin foil round a pencil to make a tube about four inches long, and hold it with one end in the middle of a candle flame. If you hold a burning match at the other end of the tube, a second flame will be lit there.Like all solid and liquid fuels, stearin produces combustible gases when heated, and these accumulate inside a flame. They burn, with the oxygen of the air, in the outer layer and tip of the flame. The unburnt stearin .....

Gas balance

23. Fix two plastic bags to the ends of a piece of wooden beading about 18 inches long and let it swing like a balance on a drawing pin. Pour some bicarbonate of soda and some vinegar into a glass. It begins to froth, because a gas is escaping. If you tilt the glass over one of the bags, the balance falls.The gas, which is given off during the chemical reaction, is carbon dioxide. It is heavier than air, so it can be poured into the bag and weighed. .....

Fire extinguisher

24. Light a candle stump in an empty glass, and mix in another glass as in the previous experiment a teaspoonful of bicarbonate of soda with some vinegar and let it froth. If you tilt the glass over the candle, the flame goes out.The carbon dioxide formed in the chemical reaction in the top glass displaces the air needed for the flame, because It is heavier, and because it is non combustible the flame is smothered. Many fire extinguishers work in .....

Burning without a flame

25. Press a handful of steel wool firmly into a glass tumbler and moisten it. Invert the tumbler over a dish containing water. At first the air in the tumbler prevents the water entering, but soon the level of water in the dish becomes lower while that in the glass rises.After the steel wool is moistened, it begins to rust. The iron combines with the oxygen in the air, and we call this process combustion or oxidation. Since the air consists of about .....

Burning iron

26. Would you have thought that even iron could be made to burn with a flame! Twist some fine steel wool round a small piece of wood and hold it in a candle flame. The metal begins to blaze and scatter sparks like a sparkler.The oxidation, which was slow in the previous experiment, is rapid in this case. The iron combines with the oxygen in the air to form iron oxide. The temperature thus produced is higher than the melting point of iron. Because of .....

Destroyed metal

27. Put a piece of aluminium foil with a copper coin on it into a glass of water, and let it stand for a day. After this the water looks cloudy and at the place where the coin was lying the aluminium foil is perforated.This process of decomposition is known as corrosion. It often occurs at the point where two different metals are directly joined together. With metal mixtures alloys it is particularly common if the metals are not evenly distributed. I .....

Electricity Potato battery

28. Stick finger length pieces of copper and zinc wire one at a time into a raw potato. If you hold an earphone on the wires, you will hear distinct crackling.produce an electric current in the same way as a torch battery,but only a very weak one. The sap of the potato reacts with the metals in a chemical process and also produces electrical energy. We speak of a galvanic cell because the Italian doctor Galvani first observed this process in a simila .....

Coin current

29. Place several copper coins and pieces of sheet zinc of the same size alternately above one another, and between each metal pair insert a piece of blotting paper soaked in salt water. Electrical energy, which you can detect, is set free. Wind thin, covered copper wire about 50 times round a compass, and holds one of the bare ends on the last coin and one on the last zinc disk. The current causes a deflection of the compass needle.In a similar expe .....

Graphite Conductor

30. Connect a torch bulb with a battery by means of a pair of scissors and a pencil. The bulb lights up.From the long tongue of the battery, the negative pole,the current flows through the metal of the scissors to the lamp. It makes it glow, and flows through the graphite shaft to the positive pole of the battery. Therefore graphite is a good conductor so much electricity flows even through a pencil lead on paper, that you can hear crackling in earph .....