What is a short hand way to sum up what occurs in a chemical reaction?

Non renewable resources like petroleum eventually

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

Answer explain why it is not possible to deduce a complete order of reactivity.