This week the Year 5 classes started their science rotations. Here are some amazing photos of Room 17 doing an experiment with Mrs Riddell in Room 15. HOW CAN RED CABBAGE BE USED AS AN INDICATOR? Red cabbage contains a chemical called anthocyanin that changes colour depending on the acidity of its environment. This means it is a pH indicator, a gauge that tells you how acidic or basic the surrounding environment is. Red cabbage is purple in a pH-neutral environment, but it turns pink in an acidic environment and bluish-green in a basic environment. The experiment the students did uses red cabbage as the pH indicator and put with different liquids, they could see which liquids are acidic and which liquids are basic.