Hot Hands, Cold Touch
The transfer of heat through direct contact between materials.
What is conduction?
Heat transfer through the movement of fluids (liquids or gases).
What is convection?
The transfer of heat through electromagnetic waves.
What is radiation?
The average kinetic energy of particles in a substance.
What is temperature?
Why does a metal bench feel colder than a wooden bench on a cool day?
Metal conducts heat away from your skin faster.
What always happens when two objects at different temperatures touch each other?
Heat moves from the warmer object to the cooler object.
Why does a metal spoon in hot soup feel hot?
Heat travels from soup → spoon through conduction.
Why does warm air rise?
Warm air is less dense than cool air.
Give an example of heat transfer by radiation.
Feeling warmth from the sun or a campfire.
When two substances reach the same temperature, and heat transfer stops.
What is thermal equilibrium?
Why do weather patterns depend on convection?
Warm air and water rise and move, forming wind and ocean currents.
Which of the following will reach thermal equilibrium the fastest: a metal pan, a plastic bowl, or a wooden spoon?
The metal pan, because metal is the best conductor.
Which material is the best conductor of heat: plastic, wood, or metal?
Metal
Describe convection in boiling water.
Hot water rises, cool water sinks, creating a convection current.
Why does wearing dark clothing on a sunny day feel hotter?
Dark colors absorb more radiant energy.
A cup of hot chocolate cools to room temperature—what’s happening?
Heat transfers from the drink to the air until equilibrium.
Why do astronauts wear reflective suits in space?
To reflect radiation from the sun and prevent overheating.
In a pot of soup heating on the stove, identify one example of conduction, convection, and radiation happening at the same time.
Conduction: pot touching burner; Convection: soup circulating; Radiation: heat from burner flame.
Why do pots have rubber or wooden handles?
They reduce heat transfer (poor conductors = insulators).
How does convection heat a room with a radiator?
Warm air near the radiator rises; cool air sinks and is reheated.
How can radiation transfer heat through space?
It does not need matter—travels in waves through a vacuum.
Why does an ice cube melt in water?
Heat flows from the warmer water to the ice until equilibrium.
Why do coastal cities have milder temperatures than inland areas?
Water absorbs and releases heat slowly, maintaining balance via convection.
A student leaves a cup of hot chocolate and a cup of ice water on the counter. After 1 hour, both are room temperature. Explain what happened in terms of heat flow and equilibrium.
Heat moved from the hot chocolate to the air and from the air into the ice water until both reached thermal equilibrium with the room.
A student touches a cold windowpane. Describe how conduction occurs.
Heat moves from the warmer hand to the cooler glass until temperatures equalize.
What happens if there is no gravity—how would convection change?
Without gravity, warm and cool fluids wouldn’t rise or sink, stopping convection currents.
How do solar panels use radiation?
They absorb radiant energy from sunlight and convert it into electrical energy.
Explain how conduction, convection, and radiation can all occur in a single system.
Example: In a pot—radiation from the burner heats the pot (conduction), and water circulates by convection.
How is thermal energy transfer important in cooking?
Conduction cooks food on contact, convection circulates hot air or liquid, radiation from the oven walls adds heat.
During a cold night, frost forms on a window. Use energy transfer terms to explain why the inside surface of the glass feels cold.
Heat from the warm indoor air transfers by conduction through the glass to the cold outside air until both sides reach thermal equilibrium.