How Does Rust Form?

Have you ever seen abandoned metals in old or under construction buildings? You might have observed a reddish-brown texture on its surface. It is called rust which occurs naturally when the metals get exposed to air and water. For example, steel and iron are the most common metals that can easily get rusted. How does rust form? You need to give a proper explanation on this to children so that they understand the concept of rusting easily. For that, explore science project ideas that can create interest in children to learn about rust in an engaging way.


Rusting is a chemical reaction when the iron is exposed to oxygen to form iron oxides. Learning chemical reactions enables children to understand the concept of rusting easily. To make it easier, you can conduct science experiments for kids so that they can relate to the information that you want them to learn. They must have seen rusted metals most of the time but would not know the reason behind its rusting. How does rust form? This is the question that children often get when they see a rusted metal. 

What is Rust?

Rust is a reddish-brown layer that happens to be appearing on the surface of metals. This is caused when the metal gets exposed to oxygen and moisture. You must have seen iron or steel kept without use for long periods of time get rusted. These metals do not come in use once they are rusted. If you expose iron to water and oxygen for many days, you will see rough texture start appearing on the surface of the iron. In other words, you can also term rust as oxidation. The rusting is possible because it is exposed to the main catalyst, which is water. The water content on the metal results in oxidation of iron. It weakens the metal and reduces its strength and durability. 

Kids must have seen abandoned cars or tools that are rusted, haven’t they? Having said that, they do not know how it got rusted. The question that comes to their mind is what is the red color material that appears on the surface of the metals. But, there is also green rust that forms when iron reacts with chloride. The main factor responsible for rusting is water. You need to make children understand what is it called and how these metals become unused once they get rusted. They might have a lot of questions in their mind, but it is important for you to solve each and every query they’ve regarding this chemical reaction. Most importantly, you need to teach them the ill effects of rusted materials which can be hazardous to health and the environment. 

Easy Science Project: How Does Rust Form?

It is not only important for children to observe the rusted materials, but also they need to understand how rust forms. Before that, they must learn the physical and chemical properties of metals to understand the rusting process easily. How does rust form? To know this, you need to conduct simple experiments for kids so that they can observe the metals getting rusted and analyze their observation in an engaging way. This can be one of the science project ideas for kids to learn new concepts related to rusting easily. 

How Does Rust Form?

Aim of the Project 

To conduct an experiment and observe rusting of metals using the materials found at home or in the classroom, and to find out which are the items that get rusted at a faster rate compared to others. 

Material Required 

  • 3 bottles
  • Water
  • Sand 
  • Vinegar
  • Iron pins


  • Keep three empty bottles with lids on the table.
  • Take a bottle and label it as A. Add iron pins inside the bottle. Then, add a handful of dry sand into it and close the lid. Keep the bottle aside. 
  • Take a bottle and label it as B. Then, add iron pins and pour enough water into the bottle. Make sure that you do not close the lid of the bottle. 
  • Take a bottle and label it as C. Then, add iron pins and vinegar into the bottle without covering the lid.
  • Keep all the bottles for 48 hours and observe the changes. 


After 48 hours, it is observed that bottles B and C showed rusting on the iron pins as there was a reaction of metals with oxygen and air. But, bottle A did not show any signs of rusting as it was not exposed to water and oxygen. The rust is formed due to a chemical reaction between iron, oxygen and water. The iron oxide reacts with oxygen to form a reddish-brown color rust on the iron Fe2O3.H2O. 

Benefits of Learning How Rust Forms

Some of the benefits of learning about the formation of rust are mentioned below:

  • Develops understanding of chemical reactions related to rusting of iron. 
  • Enhances the learning experience of children.
  • Enables children to learn about the factors responsible for rusting.
  • Creates an interest among children to learn science.
  • Develops observational and problem-solving skills in children.
  • Increases knowledge of rusting and the metals that get exposed to this reaction. 

To know more information, explore science games for kids, STEM activities for kids, science activities for preschoolers in the kids learning section at Osmo.

Frequently Asked Questions on How Does Rust Form

How does rust form?

Rusting is a chemical reaction that takes place when metals such as iron are exposed to air and water. It forms a reddish-brown covering that affects the strength and durability of metal.

What are the benefits of learning how rust forms?

The benefits of learning how rust forms is that the children will understand the chemical reactions between the metal and other factors that contribute to the rusting such as air and water. Besides this, children will develop observational and analytical skills by performing experiments at home.