Which statement describes a physical change?

Question

A.
Iron combines with oxygen to form rust.
B.
Sodium metal reacts explosively with oxygen.
C.
Calcium is added to acid and hydrogen gas is produced.
D.
Lead is heated and becomes more viscous.

Answer 1

The statement that describes a physical change is:

D. Lead is heated and becomes more viscous.

In this case, the change in viscosity due to heating does not involve a change in the chemical composition of lead. The other options describe chemical changes, as they involve the formation of new substances.