Asubstance did not change its chemical nature in a reaction. which most likely describes the reaction? a) it was heated. b) it was hit with a hammer. c) it was placed in a salt solution. d) it was frozen.

The correct answer is D

It was frozen.

Explanation:

A substance may undergo any chemical change in its nature in all the given cases except when it is frozen.

A) during heating there is chances that it undergoes decomposition . Like if calcium carbonate is heated it converts to calcium oxide and carbon dioxide.

B) When a compound is hit with a hammer there is chance of its chemical decomposition.

C) If a compound is placed in a salt solution it may react with the salt or water.

D) However freezing is purely a physical process, where contact with any other compound or any chance of chemical decomposition is not possible.

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.

i'm pretty sure its b i might be wrong though!