Rust is a naturally occurring phenomenon when certain metals are exposed to oxygen and water for a length of time. The actual chemical make-up of rust is 4Fe + 3O2 = 2Fe2O3. The only metals that rust are steel and iron. Other metals may become corroded but they do not rust. It is an actual chemical change which takes place when metal starts to rust.
Everything around us is made up of different chemicals. These chemicals are made up of atoms. The atoms can join together to create new chemicals. The atoms can also join and make up chemical compounds. Rust is a chemical compound. The iron atoms fuse together with the hydrogen and oxygen atoms. The formula for water is H2O. Adding the water creates a chemical reaction. The result can be seen as rust.
Left in a totally dry environment, iron or steel will not rust. It is when moisture is added that the oxidation process starts to occur. Because the air we breathe has moisture in it, oxidation will occur even if there is no water added to the metal. There is enough hydrogen and oxygen in the air to allow the atoms to bond with the iron. This creates the chemical reaction known as oxidation, or rust.
There are things you can do to prevent rust from forming on your metal surfaces. The first is to keep things like tools in a dry area. Rust may form even if the tools are stored in a tool box. However, the process is much slower because the exposure to the moisture in the air is decreased. If you are in a humid area, you may consider investing in a dehumidifier. This machine also decreases the moisture in the air, reducing your chances of rust forming. Things which are normally stored outside, like bicycles and lawn mowers, can be covered or moved indoors.
There are products which will allow you to keep moisture from ruining your tools and other things. Silica gel packs help to dry out the air in small places like drawers or tool boxes. Keeping a couple of these packs in your tool chest will ensure your tools are not susceptible to rust. Also, when items which are made of iron or steel become wet, dry them off as soon as possible. This keeps the oxidation process to a minimum. You can prevent rust in this manner.