How many wave cycles within the given period of time 12 seconds

What is the overall order of reaction for rate = k[no]2[o2]

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?

4al + 3o2 → 2al2o3 what does the "3" in front of o2 stand for? a) it indicates that there are 5 oxygen atoms after you add the coefficient and the subscript. b) it indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule. c) it indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction. d) it indicates that there are 3 separate oxygen molecules in the reaction.