Shanice and Jalen are doing an experiment to investigate the law of conservation of mass. They heat a solid in an open container and record the mass of the solid before and after heating. The table shows their observations.

Question

 

Solid Mass (grams)
before heating 7.5
after heating 5.5

Which best describes the conservation of mass in this experiment?

A.
The law of conservation of mass was broken in this experiment because the mass of the solid decreased.

B.
The law of conservation of mass was not broken because the mass before heating was greater than the mass after heating.

C.
The law of conservation of mass was not broken because the solid was heated in an open container, allowing gases to escape.

D.
The law of conservation of mass was broken in this experiment because the solid was heated in an open container, allowing gases to escape.

Answer 1

The correct choice that best describes the conservation of mass in this experiment is:

C. The law of conservation of mass was not broken because the solid was heated in an open container, allowing gases to escape.

In this experiment, the mass of the solid decreased because it likely transformed into gas (which escaped into the environment) when heated. The law of conservation of mass states that mass cannot be created or destroyed in a closed system. In this case, since it was an open container, some of the mass was converted to gas and escaped, meaning the mass loss is accounted for by the gases leaving the container.