Reversible and Irreversible Changes

 Reversible and Irreversible Changes

 

Reversible and Irreversible Changes- Science Animation Class 6th The changes taking place can be categorized into two parts: (a) Reversible Change  A reversible change is a change that can be undone or reversed.  A reversible change might change the colour, shape or state of a substance but it is easy to get back the original substance.  A reversible change doesn’t produce new substances. (b)Irreversible Changes  An irreversible change is a permanent change that cannot be undone.  A new material is formed, and it is not to recover the original materials.  The new material is completely different from the original material. To have a better understanding, let us learn Reversible and Irreversible changes through examples: (A) Reversible Changes (1) Melting of Ice Put some water in the freezer of a refrigerator. It will turn into ice. Can we get back ice again ? If we then warm ice it melts and changes back into water. So, this process is reversible change. (2) Folding a paper You cam fold a paper to make different shapes Does it change the property of a paper? No, only physical change in shape takes place. You can get back the original paper by unfolding. So this is reversible change (3) Dissolving salt in water Dissolve common salt in water. It dissolves in water to make a solution. Can we get back salt again? Yes, by heating the solution. When we heat the solution, water evaporates and salt remains in the beaker. In this way we get back the substance again so, this process is reversible change. (B) Irreversible Changes (1) Burning of Paper When you burn a piece of paper, it bursts into flame and gives off a lot of heat and smoke. Soon it ends up as black ash. Can we get back paper again? You cannot change the ash and smoke back to paper. A piece of paper is burnt in the flame So this burning of paper is irreversible change. (2) Germination of seed When seed is planted in soil it is germinated. The process of germination changes seed into a small plant. What kind of changes has taken place? It is an irreversible change. Because we can’t get back seed in original form. (4) Frying egg When you heat a raw egg to make a cooked egg, the fried egg cannot be changed back to a raw egg again. What kind of changes has taken place? It is an irreversible change. Because we can’t get back the raw egg in original form.