Answer:
b Different amounts of food samples were used.
Explanation:
The mass of the two samples needs to be the same in order for the test to be accurate.
The answer is Rutherford.
Answer: -
The rate decreases as the concentration of the reactants decreases
Explanation: -
A reaction involves change of the reactants into products.
Initially there is only reactants. So the rate if reaction is high.
After some time there are products. So the amount of reactant is less.
Reactions involve collisions of reactant molecules. As the reactant amount decreases, collisions between the reactants decreases. As such the rate of reaction decreases with the progress of the reaction.