The Elements: Iron

Iron is the fourth most abundant element in Earth's crust, essential for life and industry. It forms red iron oxide when exposed to oxygen and is crucial in biological processes like oxygen transport in hemoglobin and myoglobin. Mars' red color is due to iron oxide, and meteorites provide natural metallic iron. Industrially, iron is vital, forming steel when combined with carbon, used in construction. All iron on Earth originates from stars.

What is created by adding carbon to iron?

Describe the significance of iron in construction.