Autoxidation facts for kids

Autoxidation is a fancy word for a common process: when something reacts with the oxygen in the air all by itself. Think of it like a slow, quiet chemical change. It often happens to organic compounds, which are special types of chemicals found in living things and many everyday materials. A good example is when iron turns into rust – that's a type of autoxidation!

What is Autoxidation?

Autoxidation is a type of oxidation that happens when a substance reacts directly with oxygen from the air. The "auto" part means it happens automatically, or by itself, without needing a lot of outside help to get started. It's a chemical reaction where oxygen combines with another substance.

How Does Autoxidation Happen?

This process usually starts when a substance, like a metal or an organic compound, comes into contact with oxygen in the air. It doesn't need a big spark or a lot of heat to begin. Sometimes, just a tiny bit of energy, like light or a small amount of heat, can kick it off. Once it starts, it can often continue on its own in what's called a "chain reaction." This means one reaction helps start the next, and so on.

Common Examples of Autoxidation

You might see autoxidation happening all around you without even realizing it!

• Rusting: One of the most common examples is when iron turns into iron oxide, which we call rust. If you leave a metal bike or a nail outside, the iron in it slowly reacts with the oxygen and moisture in the air, forming that reddish-brown flaky stuff. This is a slow process that can weaken metal over time.
• Food Spoilage: Have you ever smelled old cooking oil or butter that smells a bit "off"? That's often autoxidation at work! The fats and oils in food react with oxygen, causing them to go "rancid." This changes their smell, taste, and even their color, making the food unpleasant or unsafe to eat.
• Rubber Cracking: Over time, rubber items like old tires or elastic bands can become brittle and crack. This happens because the rubber molecules react with oxygen in the air, which breaks down their structure and makes them less flexible.

Why is Autoxidation Important?

Understanding autoxidation is important for many reasons. For example, it helps scientists and engineers:

• Protect Materials: By knowing how autoxidation works, we can find ways to protect things made of metal, like bridges and cars, from rusting. We can also protect rubber products from breaking down too quickly.
• Preserve Food: It helps us develop better ways to store food, like using special packaging or adding ingredients called antioxidants, to keep oils and fats from going bad. This helps food stay fresh and safe to eat for longer.

Preventing Autoxidation

There are several ways people try to prevent or slow down autoxidation:

• Protective Coatings: Painting or coating metal objects can create a barrier that stops oxygen from reaching the metal. This is why cars are painted, and why some metal tools have a protective layer.
• Antioxidants: For food and some materials, special chemicals called antioxidants can be added. These chemicals act like tiny shields, stopping the oxygen from reacting with the main substance. Vitamin C and Vitamin E are natural antioxidants found in many foods.
• Storing Away from Air: Keeping things in airtight containers or in places with less oxygen can also slow down the process. This is why some foods are vacuum-sealed.

Images for kids

• 

  The cyclic mechanism of autoxidation

See also

In Spanish: Autooxidación para niños