Whether it’s our eye or your mobile phone or computer screen, they essentially showcase only 3 colours: red, green and blue, the so-called primary colours. Various combinations of these 3 colours can create all the other colours we see or those that come up on our device screens. Here, we give a set of simple materials, and an LED of each of these three colours, to create your own electronic colour mixer, using which and the power of shadows you get to see secondary and tertiary colours. Bonus: Mixture Separation – Chromatography. If you use sketch pens of different colours, and start colouring them on a filter paper, one by one, on top of each other, you will soon notice the blob turns black. These colours can then be separated by the process called chromatography, where water is drawn up using a wick and the colours separate at different radii as they interact on the wet filter paper. ThinkTac TACtivities use simple and accessible materials to develop scientific temper by observing physical realities, testing, hypothesising, questioning and analysing. Variations are designed to encourage tinkering, creating opportunities to apply logic, problem solve and think critically and creatively. All TACtivities are linked to the curriculum and help understand underlying science concepts, assisted by topic guides and videos. Our App provides access to step-by-step videos, interactive simulations, variation videos, topic guides, topic videos and exploration games for most TACtivities.
