What colors do soap bubbles have? Are they rainbow colored or clear? From where do the beautiful colors come? Let’s study the colors of soap bubbles by making them.

The ratios slightly depend on mild detergents and starches. Adjust the ratios in order to blow better bubbles. Were you able to make invisible bubbles?

There are ways to blow bubbles. To thicken the bubble wall, do not blow strongly. Dip the straw into the bubble mixture for thin bubbles. Take some pictures of the bubbles for fun.

♦  Roles of each ingredient  ♦

Mild detergents and soap solutions contain surfactants. The surfactants lower the surface tension of water, which is responsible for causing water to bead on leaves and preventing water from running down an overfilled glass. The structure of a bubble consists of a thin wall of water which is sandwiched between surfactant films. The surfactant acts to make the wall of water thin. However, as the walls get thinner, the bubbles tend to pop. So, PVA, which is found in glycerin and starch, has to be added to the mixture, and it dissolves in water making the bubbles hard to pop. The more water in the mixture, the thicker the bubble wall gets, and the more detergents in the mixture, the thinner the wall gets. If the mixture drips or bubbles easily pop, add glycerin or starch to the bubble mixture.

	Were you able to make bubbles like these?
	A thick colorless bubble	A rainbow colored bubble	A thin invisible bubble