Answer:
compound
Explanation:
"Marble is typically more than 95% calcium carbonate, perhaps even 99% calcium carbonate, and calcium carbonate is a compound. Marble has a good claim to be recognized as a compound."
Answer:
Explanation:
Driving a car (burning gas is a chemical change) and almost all the plastics we use are made by chemical reactions of different components.
Explanation:
For the given reaction:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

![Rate=k[CO]^x[H_2]^y](https://tex.z-dn.net/?f=Rate%3Dk%5BCO%5D%5Ex%5BH_2%5D%5Ey)
where x and y are order wrt to
and 
According to collision theory , the molecules must collide for a reaction to take place. According to collision theory , the rate of a reaction is proportional to rate of collision of reactants.
Thus with an increase in concentration of reactants , the rate of reaction also increases. This is because if the concentration of reactants increases , the chances of collision between molecules also increases and thus more products wil be formed which in turn increases the rate of reaction.