Dancing sodium

I want to begin with words of caution here, because this is a bit(?) dangerous. Sodium metal itself burns bare skin, gets burnt itself(although slowly) when in contact with air, kept under kerosene oil for this reason and handled with knives, tongs or suitable tools. And the amount of heat/fire that is generated here is not child's play. So be careful.

Cut a piece of the metal with knives or some tool under the kerosene sodium is kept. Cut a piece which is in noway bigger than 1cmx1cmx1cm. Next, find a metallic bucket(cannot be plastic or anything else that burns) and fill with water. Keep it in an open place, out of the house of course. Now take the piece of sodium with the tong and place it in the bucket of water. Distance yourself quickly(sometimes small explosions may follow) and enjoy the metal burning, hissing and dancing on water.

It happens because sodium, which is highly reactive, reacts with water to form sodium hydroxide - an alkali, and generates a lot of heat.

Solid state colour transformation

Take some potassium iodide and mercuric nitrate(or chloride) [all are white powders] and mix well. 1/5th of a teaspoon of each will be enough. Now, place the powder mixture on one side of a white paper. Fold the other side over the powder and rub the solid through the paper with your fingers.

The powder that has been rubbed well changes its colour from white to red, as mercuric iodide is formed.

"Where there's smoke, there's fire"

For long it has been said that where there's smoke, there's fire. That all was before the age of chemistry. Now its not a hard job to produce some nice thick white smoke without any fire at all.

You only need concentrated ammonia and concentrated hydrochloric acid solution. Dilutes will also work. If you do not have access to a laboratory or chemicals, you can get the hydrochloric acid in the open market as muriatic acid(cleaning agent) and ammonia in blue print shops.

Soak two pieces of cotton wool in each solution and keep them beside each other and experience the holy smoke.

What actuallly happens is hydrogen chloride gas evolved from hydrochloric acid and ammonia evaporated from ammonia solution comes in contact each other in mid-air and forms fine particles of ammonium chloride, which constitutes the smoke.