Have you ever heard of liquids not mixing, but forming a column instead? Well, it can be done. Here’s how you go about it.
Choose a food colour to contrast the detergent and add to water. Now, pour honey into the glass. Then, gently pour in one at a time (drip through the side of the glass) the detergent, coloured water, and then oil.
You will find that the liquids do not mix. Rather, they form a four-layered column. For added fun, try dropping in different solids (say “channa” or popcorn) into the column to observe where it will settle.
Density
A large plastic ball will float in water, whereas a metal coin will sink. Things float or sink in water based on their density. All matter is made of molecules. Density is essentially a measure of how tightly-packed with molecules something is, within a given space. An object which has its molecules packed less-tightly together in a given area is less dense. In other words, it has a lower density than one which has molecules packed more tightly. The molecules in a plastic ball are packed loosely making its density lower than that of water, while the molecules in the coin are packed tightly making its density higher. This is why the plastic ball floats while the coin sinks. Just like different solid objects have different densities, different liquids have different densities as well. Oil, which has the lowest density, floats right at the top of the four-layer column while honey which has the highest density sinks right to the bottom. The detergent floats just above the honey, and water just below the oil.
You need:
A tall transparent glass
100-150 ml of honey
100-150 ml of water
100-150 ml of liquid dishwashing detergent
100-150 ml of oil
A few drops of food colouring
Courtesy: The Science Factory, a science enrichment programme for kids.
