The Changing Phases of Matter: Liquid to Gas Phase Change

The video explains the phase change of vaporization, where a liquid turns into a gas. It covers evaporation, which occurs at the surface of a liquid, and boiling, where gas bubbles form within the liquid. The opposite process, condensation, is also discussed, where gas turns back into a liquid, as seen on cold surfaces or in cloud formation.

What is the process called when liquid water changes into gas at the surface?

• Condensation

• Evaporation

• Freezing

• Sublimation

Which of the following is an example of evaporation?

• Water boiling in a pot

• Ice melting in a glass

• Water disappearing from a mud puddle

• Steam condensing on a mirror

At what temperature does water boil at sea level?

• 0 degrees Celsius

• 50 degrees Celsius

• 150 degrees Celsius

• 100 degrees Celsius

What happens to gas particles during condensation?

• They remain unchanged

• They split into smaller particles

• They lose energy and slow down

• They gain energy and speed up

Which process is responsible for cloud formation?

• Sublimation

• Evaporation

• Freezing

• Condensation