Which of the following is not a physical change?
a. grating cheese
c. fermenting of cheese
b. melting cheese
d. mixing two cheeses in a bowl

Answer : Fermenting of cheese is not a physical change.

Explanation :

Physical change : Physical change is a change in which no new compounds are formed only changes occurs in size or state of substance. In this, there is no changes in the substance or compound.

Chemical change : Chemical change is a change in which a new compounds are formed by the chemical reaction. Changes occurs in their chemical composition and properties.

In grating cheese, only changes occurs in size of the substance. So, this is a physical change.

In melting cheese, only changes in the state ( solid to liquid). So, this is also a physical change.

In mixing two cheeses in a bowl, the composition of the substance is same, no new compounds are formed. So, this is a physical change.

In fermenting of cheese, a new substance is form by the chemical reaction. So, this is a chemical change.

Fermentation is chemical process in which substances are breakdown chemically by the bacteria, yeast or microorganism and it leads to the formation of a new compound.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.