Question

What do these two changes have in common?

melting glass
dry ice sublimating and becoming a gas

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

Answer 1

Melting glass and dry ice sublimating into gas are both caused by heating, are only physical changes, and conserve mass. They are not chemical changes as they don't alter the chemical composition of the substances involved.

Step-by-step explanation:

The commonalities between melting glass and dry ice sublimating into gas are as follows:

• both processes are caused by heating,
• they are only physical changes, and
• both conserve mass.

Regarding options given in the question:
a. Both changes involve the addition of heat, so this is correct.
b. Both melting glass and sublimating dry ice are physical changes because they involve a change of state without altering the chemical composition of the substance. Melting is the transition from solid to liquid, and sublimation is the transition from solid to gas.
c. Both processes conserve mass according to the Law of Conservation of Mass, as there is no loss of matter; it only changes its state.
d. Neither change is a chemical change, so this is incorrect.

In summary, these changes share similarities in that they involve the input of heat, are physical state changes, and during these changes, the mass is conserved.