I have a definite shape and a definite volume. What state of matter am I?
Solid
How do particles move in a solid?
They vibrate in place.
What phase change occurs when a solid becomes a liquid?
Melting
When thermal energy is added to matter, what generally happens to particle movement?
Particle movement increases.
You see particles packed closely together in an organized arrangement. What state is represented, and what evidence supports your answer?
Solid; the particles are closely packed in a relatively fixed arrangement.
I have a definite volume but take the shape of my container. What state am I?
Liquid
Which has particles that generally move faster: hot water or cold water?
Hot Water
What phase change occurs when a liquid becomes a gas?
Vaporization/evaporation
When thermal energy is removed from matter, what generally happens to particle movement?
Particle movement decreases.
You see particles close together but arranged randomly and able to move past one another. What state is represented?
Liquid.
I have no definite shape and no definite volume. What state am I?
Gas
What generally happens to particle movement when temperature increases?
Particles move faster.
What phase change occurs when a gas becomes a liquid?
Condensation
An ice cube is sitting in a warm room and begins to melt. Is it gaining or losing thermal energy?
Gaining thermal energy.
You see particles spread far apart throughout a container. What state is represented?
Gas.
My particles are close together but can slide past one another. What state am I?
Liquid
What generally happens to particle movement when thermal energy is removed?
Particles move more slowly.
What phase change occurs when a liquid becomes a solid?
Freezing
A liquid is placed in a freezer and eventually becomes a solid. Is thermal energy being added or removed?
Removed.
Two particle diagrams show the same substance. In Model A, the particles have short motion arrows. In Model B, they have longer motion arrows. Which model represents the higher temperature? Explain.
Model B; the longer arrows represent faster average particle motion.
My particles are far apart, move freely, and spread throughout their container. What state am I?
Gas
A student draws a solid with particles completely motionless. What should be corrected in the model?
The particles should be shown vibrating in place.
Water vapor cools and forms liquid droplets. Was thermal energy added or removed, and what phase change occurred?
Thermal energy was removed; condensation occurred.
A student says, “Heating matter makes the particles themselves bigger.” Explain the mistake.
The particles do not become bigger; adding thermal energy changes their motion and can change their spacing/state.
A substance changes from a solid → liquid → gas as thermal energy is added. Describe what happens to the particles during these changes.
The particles gain energy, their motion increases, and they become less constrained; the substance changes from particles vibrating in a solid to moving past one another as a liquid and eventually moving freely and much farther apart as a gas.