Can someone tell me which is which on what i put i dont know what i should put

Acombination reaction is when two or more combine to form one product. a decomposition reaction is when a substance breaks down into two or more simpler substances in a chemical reaction.

Agas expands from an initial volume of 0.040 m^3 and an initial pressure of 210 kpa to a final volume of 0.065 m^3 while its temperature is kept constant. how much work is done by the system?

·sound · parallel · mechanical · not a vacuum · needs a medium · compressions and rarefaction what type of wave is being described? a) compaction b) electromagnetic c) longitudinal d) transverse