he children will be introduced to the idea of grouping materials using a test. The properties of acids and bases will be discussed and possible tests explored. The concept of a chemical indicator will be introduced. Each child will do a science painting on “indicator paper”, pre-prepared by us, using red cabbage juice. They will paint on this paper using “chemical paints” made from lemon juice and bread soda. Children from 1st and 2nd classes will be asked to test some unknown materials (soap, citric acid, etc) to establish whether they are acids or bases.
The older children – (3rd – 6th) will also be introduced to the concept of strong and weak acids and the pH scale. The range of colours given by red cabbage juice at the various pHs will be demonstrated. The children will then be asked to investigate the “recipies” to make a range of samples – red, pink, purple, blue and green, starting with 2 colourless liquids and red cabbage juice.