The given question is incomplete. The complete question is:
A chemistry teacher carried out several demonstrations, and students recorded their observations. For one of the demonstrations, a student concluded that a physical change took place, but not a chemical change. Which of the following observations could the student have made of the results of the demonstration?
a) Two colorless solutions were combined, and the resulting solution was pink.
b) When a solid was added to a liquid, sparks were produced.
c) One piece of solid substance was changed into small pieces.
d) When two solutions were combined, a precipitate formed.
Answer: One piece of solid substance was changed into small pieces.
Explanation:
Physical change is defined as the change in which shape and size of a substance changes, There is no change in the composition of the substance as no new substance is forming. It is usually an reversible reaction.
Chemical change is defined as the change in which a change is the chemical composition takes place resulting in the formation of new substance. It is usually an irreversible reaction.
Indicators showing chemical changes are :
Color change
Characteristic odor
Formation of bubbles
Formation of precipitate
Thus the given change is a physical change as only the physical state i.e. size of solid substance was changed into small pieces.
