Chemical Reactions — Introduction to Chemical Reactions + 5 more topics

Chemical reactions are fundamental to everything from cooking to how your body works. They're essentially processes where one or more substances, called reactants, are transformed into different substances, called products. This transformation involves breaking existing chemical bonds and forming new ones.

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Chemical reactions involve breaking old bonds and forming new ones. This bond breaking requires energy input. Activation energy (Ea) is the minimum amount of energy needed to start a chemical reaction. Think of it as the "energy barrier" reactants must overcome to transform into products.

When molecules collide, they don't always react. They need to collide with enough energy and in the correct orientation. Only collisions that meet or exceed the activation energy will lead to a reaction.

When chemicals react, they rearrange their atoms to form new substances. A chemical equation is a shorthand way to represent this process.

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When chemicals react, atoms aren't created or destroyed; they just rearrange. A chemical equation is a shorthand way to represent this process.

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What does "speed up" really mean here? Every chemical reaction needs a certain amount of energy to get started – this is called activation energy. Imagine pushing a boulder up a hill; the top of the hill is the activation energy. Once it's over, it rolls down by itself. Enzymes essentially dig a tunnel through the hill, making it much easier to get the boulder to the other side. They don't change where the boulder starts or ends up, just how much effort it takes to get there.