Exothermic reactions facts for kids

An exothermic reaction is a chemical reaction that releases energy, usually as heat. Think of it like a tiny explosion or something getting warm! When an exothermic reaction happens, the stuff around it gets hotter.

What is an Exothermic Reaction?

Imagine you're holding a hand warmer. It gets warm because of an exothermic reaction happening inside! In simple terms, an exothermic reaction is a special kind of chemical reaction where substances combine and give off energy. This energy usually comes out as heat, making the surroundings feel warmer. You can even use a thermometer to see the temperature go up!

What Happens in an Exothermic Reaction?

When chemicals react in an exothermic way, they release energy that was stored inside them. This stored energy is called chemical potential energy. It's like breaking a tiny energy battery! The energy then leaves the reaction and goes into the area around it. This makes the surroundings, like the air or a container, get hotter.

Everyday Examples of Exothermic Reactions

Exothermic reactions are all around us! Here are some common examples:

• Burning: When you light a match or a campfire, you're seeing an exothermic reaction. The wood or matchstick combines with oxygen and releases a lot of heat and light.
• Neutralization: If you mix an acid with an alkali, they react and often release heat. This is called a neutralization reaction.
• Water and Calcium Oxide: When water is added to calcium oxide (also known as quicklime), it creates a lot of heat. This reaction is used in some self-heating food packages.
• Explosions: Explosions are very fast and powerful exothermic reactions. They release a huge amount of energy very quickly, causing a sudden expansion of gases and a lot of heat.

Exothermic vs. Endothermic Reactions

Exothermic reactions release heat, but there's another type of reaction that does the opposite! An endothermic reaction absorbs heat from its surroundings. This makes the surroundings feel colder. So, while an exothermic reaction makes things hot, an endothermic reaction makes them cool.

Images for kids

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  Explosions are some of the most violent exothermic reactions.

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  An exothermic thermite reaction using iron(III) oxide. The sparks flying outwards are globules of molten iron trailing smoke in their wake.

See also

In Spanish: Proceso exotérmico para niños