Provide examples of metals that are found in the earth’s crust in the free state, and mention the forms in which copper and silver are also found.

Gold and platinum are examples of metals found in the Earth’s crust in the free state, as native elements. These metals exist naturally in their elemental form without combining with other elements. Copper and silver, while sometimes found in the native state, are more commonly present in the earth’s crust as sulfide ores. Copper is often found as chalcopyrite (CuFeS₂), and silver is commonly associated with minerals like argentite (Ag₂S) or as a component of complex ores. Extracting these metals involves processes like smelting and refining to obtain the pure metal.