What causes causes earthquakes and how to survive them.
Why Tsunamis happen.
Having demonstrated irreversible changes in class, pupils were challenged to mark their own erupting volcanoes, using bicarbonate of soda and vinegar. In additional to the pictures above, a number of videos were also filmed, capturing the moment of irreversible chemical reaction (and the mess which followed!)
Irreversible changes in Science
Having explored reversible changes, separating mixtures by picking materials apart, sieving, filtering, evaporating and distilling, we moved on to consider irreversible changes. We identifying different actions in cooking change food so they cannot return to their original condition (such as eggs, cakes, toast etc.), once concrete dries is cannot be turned back to cement powder, and metal left to rust cannot be made not rusty without scraping the rust off for which part of the material is lost. In all cases, new materials are formed because of a chemical change. The same is true for burning - smoke is given off while burning and only the ashes of what was burnt remains.