Hamzah Siddiqui (H2CO3)

Carbonic acid is an acid because it has hydrogen and also a ternary ionic compound because it has more than 2 elements. It is found in rain water naturally in the air. Carbonic acid is also found in carbonated drinks like sprite and 7UP. It adds that unique sharp tasting edge in those drinks.

http://www.cooksinfo.com/carbonic-acid