Since science is such a broad subject area, there are numerous working demonstrations you could develop to present to your class. A working model is a great idea to incorporate into lessons since interactivity in this way is great for keeping children's attention, whilst also reinforcing the theory they have been learning in class.
Some good, simple working models you could produce could be;
Some good, simple working models you could produce could be;
- The electromagnet - this is a very simple demonstration to produce, requiring only a short length of iron or steel (a nail for instance), some copper wire and a battery. Wrap the copper wire around the nail to form a coil, then attach both ends of the wire to opposite poles of the battery - this is now a crude electromagnet. You could also introduce some iron filings to the experiment, these will help to illustrate the magnetism of the set-up, and also demonstrate the characteristics of a magnetic field.
- The volcano - again, this is a very simple demonstration to produce, but requires a little preparation before presenting to the class. First take a suitable container, such as a small plastic soft drink bottle, to form the volcano 'crater'. Build a cone-shaped surround around the bottle to form the volcano; this can be done using foam or cardboard. Paint the surround to give a realistic volcano appearance - you could even add some trees, cars etc for some realism! Now for the important science part, and what your class will all be waiting for - the explosion. Add a measured amount of bicarbonate of soda to the concealed bottle (you should experiment with proportions prior to the experiment to obtain the desired ferocity) and add a little red/orange poster paint to the mix to give the lava its color. Finally, when you are ready for the eruption, add vinegar to the bottle. This will react with the bicarbonate of soda to form carbonic acid, an unstable substance which immediately decomposes into water and carbon dioxide; forming a bubbling lava-like reaction.
