Answer:
Chemical change
Explanation:
A chemical change is what happens. The food digested changes smell due to some enzyme the has acted on the food which catalyzes the rate of digestion. The enzymes acts on the food in order to speed up the rate of the reaction (digestion) and in turn causing the smell.
I believe the answer would be c because i think that you multiply the 2
The answer would be 20000
The answer in standard form/scientific notation would be 2 x 10^4
(The exponent is 4 because that's how many digits after the 2 there is)