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Catalyst — অনুঘটক
Quick answer
A catalyst is a substance that speeds up a chemical reaction yet remains chemically unchanged when the reaction is over.
Definition
A catalyst speeds a reaction by offering an alternative pathway of lower activation energy, so far more collisions succeed; a small amount can process a large mass of reactants. It is not used up, and it does not change the products or the heat released — only the speed. Enzymes are nature's catalysts: the amylase in your saliva breaks the starch of chewed rice into sweet-tasting sugar within a minute or so.
For example
In the school lab, a pinch of makes hydrogen peroxide fizz out oxygen at once; without the catalyst the same bottle sits quietly for days.