You will need:
- Simple wire hanger
- Woollen string
- Liquid dish-washing soap
- Tub of water
Learn something new while discovering a
unique and fun way of entertaining your friends.
INSTRUCTIONS
- Fill a tub with some water and mix a good amount of liquid dish-washing soap into the water to create a frothy solution.
- Next, take the wire hanger, and ask an adult to help you bend it so that its shape may be changed into a circle.
- Take 1 long string of wool and tie it across the diameter of the circle in such a way, that you create an eye shape in the centre with the wool.
- Now, gently take this contraption and soak it into the tub of soapy water.
- Pull it out of the soap-water solution. Make sure that the entire circle is covered with a bubble.
- Without bursting the entire bubble, try bursting the bubble formed within the two pieces of wool. What happens?
- Repeat the experiment again, this time bursting the left or right side, in between one of the woollen strings and the circumference of the wire hanger.
RESULT
Since the surface tension of the soapy bubble pulls the string from both sides, the woollen string remains loose. However, when you burst the bubble in the centre, the surface tension is greater on the outer sides of the woollen string, pulling the string apart and shrinking the film of the bubble, leaving a clear gap in the middle with bubbles on the side. The reason why bubbles are not square or triangular in shape is surface tension. The smallest amount of the area of air is covered by the film of soapy water in the form of a sphere. This soapy
film gets pulled tight from everywhere creating a sphere.
