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An exothermic reaction releases heat into its surroundings, while an endothermic reaction absorbs heat from its surroundings.
In more detail, an exothermic reaction is a chemical reaction that releases energy by light or heat. This is the type of reaction that most people think of when they hear the word 'reaction'. It's the kind of reaction that occurs when you light a fire, or when a bomb explodes. The energy that is released in an exothermic reaction is usually transferred to the surroundings in the form of heat, which is why the surroundings get hotter. This is because the energy needed to break the bonds in the reactants is less than the energy released when new bonds are formed in the products.
On the other hand, an endothermic reaction is a chemical reaction that absorbs energy from its surroundings. This energy is usually in the form of heat, but it can also be in the form of light. An example of an endothermic reaction is photosynthesis, where plants absorb light energy from the sun and use it to convert carbon dioxide and water into glucose and oxygen. In an endothermic reaction, the energy needed to break the bonds in the reactants is greater than the energy released when new bonds are formed in the products. This is why the surroundings get colder during an endothermic reaction.
In terms of energy diagrams, exothermic reactions have a lower energy level for the products than for the reactants, indicating that energy has been released. Conversely, endothermic reactions have a higher energy level for the products than for the reactants, indicating that energy has been absorbed.
It's also worth noting that whether a reaction is exothermic or endothermic can often determine whether it will occur spontaneously. Exothermic reactions are often spontaneous because they result in a release of energy, making them more likely to occur without the need for additional energy. However, endothermic reactions require an input of energy, which means they may not occur without an external energy source.
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