When a cup of hot chocolate is heated from 80 C to 90 C, which of the following is happening to the molecules of the liquid?
a
The motion of the molecules will stay the same.
b
The motion of the molecules will stop.
c
The motion of the molecules will speed up.
d
The motion of the molecules will slow down.
c) The motion of the molecules will speed up.
When heat is added to a substance, the kinetic energy of its molecules increases, causing them to move faster and collide more frequently. As a result, the temperature of the substance increases. So, when a cup of hot chocolate is heated from 80 C to 90 C, the motion of the molecules will speed up.
c) The motion of the molecules will speed up.
Why did the molecule join the gym? Because it wanted to increase its "hot"-ivity!
c
The motion of the molecules will speed up.
When a cup of hot chocolate is being heated, the temperature of the liquid is raised from 80°C to 90°C. With this increase in temperature, the kinetic energy of the molecules within the liquid also increases.
According to the kinetic theory of matter, the temperature of a substance is directly related to the average kinetic energy of the particles in that substance. In other words, as the temperature increases, the average speed and motion of the molecules also increase.
Therefore, the correct answer is c) The motion of the molecules will speed up.