* Mixtures are combinations of two or more substances that are not chemically bonded. The substances in a mixture retain their individual properties.

* Compounds are formed when two or more elements chemically combine in a fixed ratio.

Coins are made up of different metals (like copper, nickel, zinc, etc.) that are physically combined. These metals do not chemically react to form new substances. You can often see the different metals within a coin.

For example, a US penny is made of copper-plated zinc. The copper and zinc remain distinct, even though they are combined in the coin.