The diatomic nitrogen gas molecule (N₂) is a colorless, odorless, and tasteless gas, making up 78.1% by volume of atmospheric gas that we breathe.  Nitrogen is present in all living organisms including protein. The ion (N^-) combines with oxygen to form different compounds in the atmosphere, especially nitrogen dioxide (NO₂) which is a reddish-brown gas with a characteristic sharp odor.  It is one of the poisonous gases found in smog as an air pollutant harmful to humans.  Nitric acid (HNO₃) is highly corrosive and toxic causing severe burns.  

Carbonate ion (CO₃^-2 ) is a polyatomic ion  that bonds with calcium to form calcium carbonate (CaCO₃).  The carbonate ion binds with many other cations and the family is called “carbonate salts.”  There are also many minerals that belong to the carbonate family.  They can be readily identified because if you put an acid on the mineral, it will fizz.  Calcium carbonate is given the mineral name, calcite and is very common mineral.