When measuring the mass of a condensed volatile liquid collected, you need to correct its mass by the mass of the air lost in the process. What information do you need to complete this correction

Contrast the force of gravity between these pairs of objects: 1-kg mass and a 2-kg mass that are 1 m apart; a 1-kg mass and a 2-kg mass that are 2 m apart; and two 2=kg masses that are 1 m apart. i dont understand.