A lab technician places a larger Ziploc® bag on a pan of a technical balance and records the mass (mass A). The bag is completely deflated and weighs 6.42 g. She then opens the bag so that it is now filled with air (i. e. it looks like a little pillow) closes it, places on the same balance and records the mass (mass B). Note that the bag is filled with air which is at atmospheric pressure. What is the relation between the two masses?