B. move farther apart
Explanation:Note that:
• The higher the temperature of a substance, the higher the kinetic energy possessed by its molecules
,• The higher the kinetic energy possessed by the molecules, the higher their speed of motion
,• The molecules of a gas have higher kinetic energy, hence they collide with each other and with the wall of the container.
When water is heated from 25°C to a gas at 100°C, the molecules posses higher kinetic energy(due to increase in temperature). Therefore, they move farther apart.
