Question

What do these two changes have in common?

- stapling an envelope shut
- an iceberg melting slowly

Select all that apply.
a. Both conserve mass.
b. Both are only physical changes.
c. Both are chemical changes.
d. Both are caused by cooling.

Answer 1

Both stapling an envelope shut and the melting of an iceberg are physical changes where the properties of the material change, but the identity of the matter remains the same.

Step-by-step explanation:

Both stapling an envelope shut and the melting of an iceberg have in common that they are physical changes. A physical change is a change to a sample of matter in which some properties of the material change, but the identity of the matter does not. In the case of stapling an envelope shut, the shape of the envelope changes, but the composition of the paper and the staples remains the same. Similarly, when an iceberg melts, its shape changes as it acquires the ability to flow, but its composition, which is primarily water, remains the same. Both changes do not involve the formation of new substances, so they are physical changes and not chemical changes.