Mrs. Clark decides to do a demonstration for her class with a piece of notebook paper. Using a balance, Mrs. Clark discovers that the mass of the paper is 20 g. She then takes the piece of paper and cuts it into several small pieces. The cumulative mass of the small pieces is 20 g. What has Mrs. Clark demonstrated for her class?

Question

A.
a physical change involving change of shape and size of matter
B.
a chemical change involving change of mass
C.
a physical change involving change of mass
D.
a chemical change involving change of shape and size of matter

Answer 1

Mrs. Clark has demonstrated:

A. a physical change involving change of shape and size of matter.

This is because cutting the paper into smaller pieces alters its shape and size, but does not change its chemical composition or mass. The total mass remains 20 g, which is consistent with the principle of conservation of mass during a physical change.