A student heated a 10 g sample of a compound in an open container. A chemical reaction occurred. The mass of the sample was measured again and found to be less than before. Which of the following explains the change in mass of the sample? a
The heat caused the compound to become less dense.
b
The reaction gave off more heat than was added.
c
Some of the lighter atoms were converted to energy.
d
One of the reaction products was a gas.