Which process is an example of a chemical change?

A metal railing rusting in damp weather

alcohol evaporating from a cotton swab

steam rising from a boiling pot of soup

a piece of wood shrinking as it dries out

A chemical change produces a new substance, while physical changes don't. In the case of the alcohol evaporating, it's still alcohol in the end, but it's now a gas. With the steam rising, it's it's still water. The wood loses some water but it's still wood, so the only possible answer would be the rusting on the railing because rust is a different type of material than the object that went under the transformation.

thank you

Thank you Ann

The process that is an example of a chemical change is a metal railing rusting in damp weather.

To determine this, we can look at the characteristics of a chemical change. A chemical change involves the formation of new substances with different chemical properties than the original substances. In this case, the metal railing reacts with the moisture in the air to form rust, which is a different substance with different properties than the original metal.

On the other hand, the other processes mentioned are examples of physical changes rather than chemical changes. Let's go through them briefly:

- Alcohol evaporating from a cotton swab is a physical change. Evaporation is a physical process where a liquid changes into a gas, but the alcohol itself remains the same substance.
- Steam rising from a boiling pot of soup is also a physical change. It is the result of water being heated, causing it to change from a liquid to a gas (water vapor), but the substance itself remains water.
- A piece of wood shrinking as it dries out is again a physical change. It is a result of the wood losing moisture and becoming smaller, but the chemical composition of the wood remains the same.

Therefore, based on the definition of a chemical change, the metal railing rusting in damp weather is the example of a process that involves a chemical change.

wood as it dries out