Heat Temperature and State
What is temperature a measure of?
A. The amount of matter in a substance
B. The average kinetic energy of particles
C. The total heat energy stored
D. The density of the particles
The average kinetic energy of particles
What does the Law of Conservation of Energy state?
Energy cannot be created or destroyed, only transformed
Heat always flows from:
A. Warmer to colder objects
B. Colder to warmer object
Warmer objects to colder objects
Which state of matter has particles that move freely and are far apart?
A. Solid
B. Liquid
C. Gas
D. Plasma
GAS
Which of the following best explains how scientific knowledge changes over time?
A. Scientists vote on the best explanation
B. Once a theory is created, it never changes
C. New evidence can support or challenge existing explanations
D. Scientific ideas are based on opinions
New evidence can support or challenge existing explanations.
Which process requires heat to be added to a substance?
A. Freezing
B. Condensation
C. Melting
D. Deposition
Melting
When a pendulum swings, its energy repeatedly changes between:
Potential and kinetic energy
Which type of heat transfer occurs when warm air rises and cool air sinks?
Convection
When you rub your hands together, what transformation occurs?
Mechanical → Thermal
A scientist discovers new data that does not fit an existing scientific explanation. What should happen next?
A. Ignore the new data
B. Change the data to match the explanation
C. Revise the explanation based on the new evidence
D. Stop doing research
Revise the explanation based on the new evidence
What happens to particle movement when heat is added to a substance?
Particles speed up
When energy transforms from one type to another, the total amount of energy:
A. Increase
B. Decrease
C. Stay the same
Stays the same
Why does warm air rise and cool air sink?
Warm air is less dense, so it rises; cool air is more dense, so it sinks. This creates convection currents.
A campfire provides warmth and light. What energy transformations occur?
Chemical energy in wood → thermal and radiant energy (heat + light).
Give one example of a scientific idea that changed because of new evidence.
Why does ice remain at 0°C while melting even though heat is still being added?
because all added heat is used to break the bonds between particles, not raise temperature. This is called latent heat.
When a microwave heats food, what energy transformations happen, and how does this follow the Law of Conservation of Energy?
Microwave:
Electrical energy → radiant (microwave) energy → thermal energy in the food.
Energy only changes form.
A student puts an ice cube in a warm room. Explain the direction of heat flow and why the ice melts.
Heat flows from the warm air into the colder ice cube, causing the ice to gain thermal energy and melt.
In a solar panel, radiant energy is transformed into:
Electrical Energy
Explain the difference between a scientific theory and a scientific law.
Explain the difference between heat and temperature.
A student claims, “When ice melts, the energy disappears.”
Explain why this statement is incorrect.
Energy does not disappear; it is used to break bonds between particles.
Thermal energy becomes stored potential energy in the liquid state.
A pot of water is heated on a stove. Describe all three types of heat transfer occurring in this situation.
Conduction: Heat moves from the stove to the pot.
Convection: Warm water rises, cool water sinks.
Radiation: Heat from the stove coils may radiate outward.
A hydroelectric dam generates electricity. Explain the energy transformations involved.
Kinetic Energy → Mechanical Energy → Electrical Energy
Why is repeatable evidence important in science?
Repeatable evidence shows that results are reliable and not due to chance.