States of Matter
This state of matter has a definite shape and a definite volume.
What is a solid?
In which state are particles packed closely together in fixed positions?
When matter is heated, it gains this type of energy.
What is thermal energy?
Solid → Liquid
What is melting?
An ice cube is left outside on a warm day. What will eventually happen?
It will melt
This state of matter has a definite volume but takes the shape of its container.
What is a liquid?
True or false: Particles in a solid do not move.
False. They vibrate in place.
Adding thermal energy generally causes particles to do this.
Move faster
Liquid → Solid
What is freezing?
Water droplets appear on the outside of a cold cup. What change of state occurred?
Condensation
This state of matter has no definite shape or definite volume.
What is a gas?
In which state are particles far apart and moving freely?
What is a gas?
Removing thermal energy generally causes particles to do this.
Move slower.
Liquid → Gas
What is vaporization?
A student says, “When water evaporates, the water particles disappear.” Is the student correct?
No. The water particles still exist; the water changed from liquid to gas.
Water, milk, and juice are examples of what state of matter?
What generally happens to particle motion when temperature increases?
The particles move faster / their average kinetic energy increases.
Which generally has particles with greater average kinetic energy: hot water or cold water?
Hot water
Gas → Liquid
What is condensation?
If thermal energy is continually removed from liquid water, predict what will eventually happen.
The water will freeze/change into a solid.
Explain one major difference between a solid and a gas.
A solid has a definite shape and volume, while a gas has neither a definite shape nor definite volume.
Compare the particles of a liquid with those of a solid.
Liquid particles remain close together but can move past one another, while solid particles vibrate around relatively fixed positions.
Explain the relationship between temperature and the average kinetic energy of particles.
As temperature increases, the average kinetic energy of the particles increases; as temperature decreases, it decreases.
A piece of dry ice changes directly from a solid to a gas. Name this process.
What is sublimation?
Explain why heating a substance can cause it to change state.
Adding thermal energy increases particle motion. With enough energy, the particles can overcome attractions and rearrange into a different state of matter.