Rang a Cúig caused quite a stir when they explored the concept of density using household liquids like cooking oil, washing up liquid, honey,  milk, food colouring and water. Each liquid formed a separate layer with the least dense liquid, cooking oil, settling on top and the most dense liquid, honey, sinking to the bottom. They also investigated chemical reactions and the release of carbon dioxide when coke and Mentos mints are combined explosively. Defintely an experiment for outdoors!