A balloon is inflated with room- temperature air and then put in a
sunny place. The balloon expands
slightly due to a rise in
temperature.
Describe the molecules of air
inside the balloon when the
balloon is left in the sunlight as
compared to when it was first
inflated.

The correct answer would be b) volume versus temperature, because they are also directly proportional.

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).