A table tennis ball was dented. A student explained that she knew she could fix the dent in the ball. She placed the table tennis ball in boiling water. A few minutes later, because of the higher temperature, the ball popped into its round shape again. She knew that when the dent was fixed, the gas took up more volume. What else changed in the gas during this increase in
volume?

The pressure of the gas in the table tennis ball decreased.

The density of the gas in the table tennis ball decreased.

The number of molecules of the gas in the table tennis ball increased.

The density of the gas in the table tennis ball increased.