The students in mr. black's class are studying about gases and earth's atmosphere. mr. black placed a deflated soccer ball on the balance. the balance read 560 grams. next mr. black took out a bicycle pump and pumped the soccer ball up until it was nice and round. he put the ball back on the balance and read 570 grams! with this experiment, mr. black just showed his students that air a) has mass. b) has weight. c) takes up space. d) is made up of oxygen and nitrogen.