Explain how heat would change the density of a parcel shape

Answer: The parcel's density will decrease.

When the parcel is heated, the air molecules in the parcel will move at a faster rate and there will be more collisions. Since the molecules, will expand due to heat the volume would increase. The air is heated and is lighter than cold air so the hot air rises quicker and will make the parcel less dense. The pressure, however, will increase due to a parcel is a closed container.