Are you looking for some really cool ideas for a science experiment? Then check out this awesome video of what happens when a pound of sodium metal is tossed into a river. Isn’t that cool?!
So, when you mix salt into water, normally you get a safe product like salt water, however under special conditions, mixing the two can result in a massive explosion. First let us see the properties of sodium, then analyse the experiment.
Sodium (Na); Atomic number 11, is a soft metal. It is reactive with a slow melting point. It is also one of the most important alkaline metals. Elements like water, even snow or ice bring out the swift reactions of this element. Sodium is nothing but salt. Billions of years ago, the sodium from rocks got washed out and settled into the oceans and remained there. The water in the seas contains up to 11,000 ppm (parts per million) sodium and the river waters around 9 ppm.
The powdered form of sodium is highly explosive and can also be poisonous when it reacts with certain other elements.
About this science experiment:
As sodium chloride has less density, it floats when added to water. When the elements come in contact, they produce hydrogen gas below the water line, in turn releasing heat. The ball of molten vaporises the water and the vapour separates water and the hot surface.
Unlike liquid tin, the molten salt doesn’t have surface tension. So, the sphere is created but the water enters into those cracks. The volume of the liquid expands up to 1800 times inflating the local area around the cracks. The expansion that takes place travels faster than the speed of sound making it a supersonic shock wave. This is the reason behind the explosion or the “boom”.
Note: Do NOT try this with any supervision!