Which of the following situations would cause the greatest decrease in the motion of molecules in a system?
A. The system absorbs 75 J of heat, and its volume doubles.
B. The system releases 75 J of heat, and its volume is halved.
C. The system absorbs 75 J of heat, and its volume is halved.
D. The system releases 75 J of heat, and its volume doubles.

What defines the mass number of an isotope? a. the sum of the neutrons and protons b. the sum of the neutrons and electrons c. the number of neutrons d. the number of protons

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

The mass of a bowling ball is 10 kg and the mass of a ping pong ball is 0.015 kg. if the two objects are 5 meters apart, what is the gravitational force ?