Lesson 3: Particles in Motion – We learned about heat and changes of state. When thermal energy is added to solid ice its temperature increases until it starts to melt changing to liquid water. When thermal energy is removed from liquid water its temperature decreases until it starts to freeze changing to solid ice. Then we learned that when thermal energy is removed from a gas it changes to a liquid through a process called condensation. Next we learned that sublimation occurs when a solid absorbs energy and changes directly to a gas without first becoming a liquid. Deposition occurs when a gas changes directly to a solid without first becoming a liquid. Then we learned that thermal energy moves quickly in a thermal conductor and slowly in a thermal insulator.
Discussion Question:
Describe the changes in energy and temperature that occur when something frozen changes to water.
As the ice absorbs energy from its surroundings, the temperature rises until the ice starts to melt. The melting ice continues to absorb energy while it melts but its temperature does not change until all the ice is melted. The temperature of the liquid water rises until the water starts to vaporize. The temperature does not rise while vaporization occurs.