States of Matter
Describe the movement of molecules in a solid.
Molecules vibrate in place and are locked in position.
What is thermal expansion?
When substances expand due to molecules moving faster and further apart.
Does heat transfer from hot to cold or cold to hot?
Hot to cold.
What type of energy is stored in a battery?
Chemical energy (potential).
What does the Conservation of Energy Law state?
Energy cannot be created or destroyed, only transferred or transformed.
What state of matter has the fastest-moving molecules?
Gas
How does adding thermal energy affect the movement of particles?
Particles move faster and spread further apart.
Name the three types of heat transfer.
Conduction, convection, and radiation.
What type of energy is motion energy?
Kinetic energy.
Explain how energy is conserved when heating a pot of water.
Heat transfers from the stove to the pot, then to the water—no energy is lost.
Compare the movement of molecules in a liquid vs. a gas.
Molecules in a liquid move freely but slower than in a gas, where they move the fastest and most freely.
What happens to the volume of a liquid when heated?
The volume increases due to thermal expansion.
Why does a metal spoon in hot cocoa become warm?
Thermal energy transfers from the hot cocoa to the cooler spoon through conduction.
Is thermal energy kinetic or potential? Why?
Kinetic, because it comes from the movement of particles.
Describe how energy transfers but is not lost.
Energy moves from one object to another without disappearing; the total amount of energy remains the same.
In which state are molecules locked in place?
Solid
Why do substances expand when heated?
Increased thermal energy makes particles move faster and take up more space
Why does a person feel cold when touching snow?
Heat transfers from the warmer hand to the colder snow.
What kind of energy does a stretched rubber band have? Why?
Potential energy, because it is not moving.
Give an example of energy transfer through convection.
Warm water rising and cooler water sinking in a heated pot.
Explain what happens to molecules when a gas cools down.
The molecules slow down and move closer together.
How does decreasing thermal energy affect particle movement?
Particles slow down and move closer together.
Explain conduction using an example.
Touching a hot pan transfers heat to your hand through direct contact.
What is the main difference between potential and kinetic energy?
Potential energy is stored; kinetic energy is the energy of motion.
How does the Conservation of Energy Law apply to a cooling cup of tea and when does the energy transfer stop?
Heat transfers from the tea to the surrounding air until they reach the same temperature.