Conduction
What is Conduction?
Heat moving through direct contact
What is convection?
Heat transfer through the movement of liquids or gases
Which type of heat transfer does NOT require matter?
Radiation
In which direction does thermal energy naturally transfer?
Warmer objects to cooler objects
What happens to particles when the temperature of a substance increases?
Their average kinetic energy increases
Which example best demonstrates conduction?
A. The Sun warming Earth
B. Warm air rising above a heater
C. A metal spoon becoming hot in soup
D. Feeling heat from a campfire
C. A metal spoon becoming hot in soup
Which is the best example of convection?
A. A spoon heating up in soup
B. Sunlight warming your skin
C. Warm air rising above a radiator
D. Touching a hot pan
C. Warm air rising above a radiator
Which example demonstrates radiation?
A. A metal spoon getting hot
B. Warm water circulating in a pot
C. The Sun warming Earth's surface
D. A hand touching a hot surface
C. The Sun warming Earth's surface
Why does an ice cube melt when placed in a warm room?
The ice absorbs thermal energy from its warmer surroundings
What happens to particles when a substance cools?
Their average kinetic energy decreases
Why does a metal seat feel cold when you touch it?
Thermal energy transfers from your hand to the cooler metal
What happens to warm water during convection?
It rises because it becomes less dense
Why can the Sun transfer thermal energy to Earth?
Radiation can travel through the vacuum of space
A bottle of water at 21°C is placed in a refrigerator at 4.5°C. What happens?
Thermal energy moves from the warmer water to the cooler air
When a solid is heated, what happens to its particles?
A. They stop vibrating
B. They vibrate more vigorously
C. They lose all kinetic energy
D. They immediately become a gas
B. They vibrate more vigorously
A cook places a metal pan on a hot burner. How does conduction occur?
Thermal energy transfers from the burner to the pan through direct contact
When water boils in a pot, what causes convection currents?
Hot water rises while cooler water sinks
A student stands with their back toward a campfire. Why does their back feel warmer than their chest?
Thermal radiation travels from the fire toward their back
What is thermal equilibrium?
When objects reach the same temperature and there is no net thermal energy transfer between them
What can happen when a solid absorbs enough thermal energy?
A. Its particles stop moving
B. It becomes colder
C. Its particles overcome their fixed positions and the solid melts
D. It loses all its thermal energy
C. Its particles overcome their fixed positions and the solid melts
A metal nail heated to 100°C is placed into water at 20°C. What will happen?
The nail transfers thermal energy to the water until they reach the same temperature
A pot of water is heated on a stove. Which TWO heat transfer processes are happening?
Conduction from the burner to the pot and convection within the water
How can a heat lamp warm an object without touching it?
By transferring thermal energy through electromagnetic waves
An ice cube at −2°C is warming in a room at 20°C. Its temperature remains at 0°C for several minutes while melting. Why?
The energy being absorbed is used to change the ice from solid to liquid.
A student observes that particles in a substance are moving faster and spreading farther apart. What conclusion is MOST reasonable?
A. The substance is losing thermal energy
B. Its temperature is decreasing
C. Its particles have lost kinetic energy
D. Its temperature is increasing
D. Its temperature is increasing