Is carbonation an example of a chemical reaction?
No. Carbonation is simply dissolving carbon dioxide gas in a liquid. Only indirect chemical change occurs, and if you just let the carbonated liquid sit for a while, it will reverse itself. A chemical reaction involves the destruction and or formation of bonds, which does not occur during the carbonation proper. Thus carbonation is a physical change, not a chemical one.
However, under pressure, water and carbon dioxide form carbonic acid (H20 + CO2 -> H2CO3) which makes most carbonated beverages slightly more acidic. This change reverses itself when normal atmospheric conditions are restored.
Please see: http://en.wikipedia.org/wiki/Physical_change http://en.wikipedia.org/wiki/Chemical_reaction http://en.wikipedia.org/wiki/Carbonation
A piece of wood by itself is not an example of a chemical reaction. However, when the wood is burned, it chemically combines with oxygen in the air, producing mostly water and carbon dioxide. Because new chemical substances are created in this combustion reaction, the burning of wood is a good example of a chemical reaction.
In a chemical reaction the starting materials are treated as reactants. A chemical reaction example: N2 (nitrogen) + 3H2(hydrogen) <=> 2NH3 (ammonia), Nitrogen and hydrogen are considered as chemical reactants. In any chemical balance equation left-hand compounds are called as chemical reactants. Another example of the above is "the chemical reagent".