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Endothermic process facts for kids

Kids Encyclopedia Facts

An endothermic process is a scientific term for something that takes in energy, usually as heat, from its surroundings. Think of it like a sponge soaking up water. When an endothermic process happens, the area around it often feels cooler because the process is absorbing heat.

This can be a chemical change, like when you dissolve certain salts in water and the water gets cold. It can also be a physical change, such as ice melting. When ice melts, it needs to absorb heat from the air to turn into liquid water.

The word "endothermic" comes from ancient Greek words meaning "within" and "hot" or "warm." It was first used by a French chemist named Marcellin Berthelot. The opposite of an endothermic process is an exothermic process, which releases energy, often as heat.

What Happens in Chemistry?

In chemistry, endothermic reactions happen when more energy is needed to break chemical bonds than the energy released when new bonds form. Imagine you have two LEGO bricks stuck together (a bond). To pull them apart, you need to use energy. If you then connect them to other LEGO bricks, new bonds form, and this might release some energy.

If the energy you needed to pull the first bricks apart is more than the energy released when you connect them to new ones, then the whole process ends up taking in energy from its surroundings. This is an endothermic reaction.

Examples of Endothermic Processes

Many everyday things are endothermic processes:

  • Evaporation: When water turns into vapor, like sweat drying on your skin, it takes heat from your body, making you feel cool.
  • Sublimation: This is when a solid turns directly into a gas without becoming a liquid first. Dry ice (solid carbon dioxide) doing this is a good example; it absorbs heat from the air.
  • Melting: Ice cubes melting in a drink absorb heat from the drink, making the drink colder.
  • Instant Cold Packs: These often contain chemicals like ammonium nitrate. When you break the inner pouch, the chemicals mix with water and dissolve. This dissolving process is endothermic and absorbs heat, making the pack feel cold.
  • Baking Soda and Citric Acid: When you mix baking soda and citric acid (like in some bath bombs or fizzy drinks), they react and absorb heat, sometimes making the mixture feel cool.

Endothermic vs. Endotherm

These two words sound similar and come from the same Greek roots, but they mean different things depending on if you are talking about chemistry or biology.

  • Endothermic (in chemistry): This describes a process where a system takes in energy, usually heat, from its surroundings.
  • Endotherm (in biology): This refers to an animal that can keep its body warm from the inside, using heat made by its own body functions. Humans are endotherms. Animals like lizards are ectotherms, meaning they rely on outside heat sources like the sun to warm up.

See also

Kids robot.svg In Spanish: Proceso endotérmico para niños

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