An example of an extensive property of matter is "mass"
The answer to your question would more than likely be chemical energy, natural gas, and chemical energy. but I don't know what grade your in I'm in eighth if your below I know the answer. I'm pretty sure I had a question exactly like this last year but that was last year so if it's wrong sorry. I looked it up on Google to make sure
i think it is Synthesis Reaction because in a synthesis reaction one or more simple substances combine to form a more complex substance.
If there is two or more reactions yilding one product is another way to identify a synthesis reaction.
For the chemical equation for this synthesis reaction really looks like:
reactant +reactant = product
if im wrong correct me but have a blessed day/night
=)
