Bill left a hammer out in the rain all day. The next morning it had rust on it. Oxygen and a metal chemically combine to form rust. What is rust an example of? a. A mixture b. An element c. A solution d. a compound

d. a compound

Explanation:

Rust is also known as "iron oxide." It is a compound that is very common around the world. This compound is formed because iron readily combines with the element, oxygen. This is the reason why it is not common to find pure iron in the environment. The process of an iron rusting is called "corrosion."

The speed of rusting largely depends on the electrolytes present. Rain is considered a better electrolyte that speeds up the rusting of the iron than pure water. Thus, this is the reason why Bill's hammer had rusts on it the next morning.

answer; convade;