Comment on native and combined states of metals.

The definition of the native state:

When a metal is found in its elementary or uncombined form in the earth's crust, it is said to occur in a free or native state. In the native state, metals that are very unreactive lying at the bottom of activity series are found in the native state. These are unaffected by moisture, Carbon dioxide (${\mathrm{CO}}_2$) in the air, or other non-metals, and have no tendency to react with Oxygen (${\mathrm{O}}_2$).

Example: Copper ($\mathrm{Cu}$), Gold ($\mathrm{Au}$), Silver ($\mathrm{Ag}$) and Platinum ($\mathrm{Pt}$) etc.

The definition of the combined state:

If a metal is present in nature in the form of its compounds, it is considered in a combined state. Copper ($\mathrm{Cu}$) and silver ($\mathrm{Ag}$) are metals that exist in both their native and combined states.

Example: Sodium ($\mathrm{Na}$), Magnesium ($\mathrm{Mg}$) etc.