Which term refers to a metal that is not formed from iron?

The term that refers to a metal not formed from iron is "non-ferrous metal." Non-ferrous metals include a variety of materials such as aluminum, copper, lead, nickel, and zinc, which do not contain significant amounts of iron. This classification is important in both industrial and consumer applications, as non-ferrous metals typically offer advantages such as resistance to corrosion, lower density, and improved conductivity compared to ferrous metals.

Ferrous metals, in contrast, are those that contain iron and are typically magnetic and prone to rusting when exposed to moisture. Alloys are mixtures of two or more metals (or metals and other elements) where at least one component is a metal, which means they can include both ferrous and non-ferrous metals depending on their composition. Reactive metals, such as lithium or sodium, are those that readily react with other elements, often forming compounds, but this term does not specifically address whether the metal contains iron or not.

Therefore, identifying non-ferrous metals is crucial for understanding their properties, applications, and benefits over ferrous alternatives, which is why it is the correct answer.