Heat basics
Heat Basics 100 — What is temperature a measure of in matter?
Heat Basics 100 — Temperature measures the average kinetic energy of the particles in a substance.
Energy Transfer 100 — Name the three main methods by which thermal energy moves from one place to another.
Energy Transfer 100 — Conduction, convection, radiation.
Experiments & Data 100 — In the students’ experiment, which substance (rock, copper, or plastic) caused the water’s temperature to drop the most over 4 minutes?
Experiments & Data 100 — Rock (it caused the largest drop in water temperature over time).
Equilibrium & Temperature 100 — If the temperature of a gas in a sealed container drops, do the particles move faster or slower? Explain.
Equilibrium & Temperature 100 — Slower. When temperature drops, particles have less kinetic energy and move more slowly.
200 — True or False: Adding more of a substance always increases the average kinetic energy of its particles.
200 — False. Adding more substance increases total thermal energy but does not necessarily change the average kinetic energy (temperature).
200 — Give an example of conduction from everyday life.
200 — Example answer: Holding a metal spoon in a hot cup of soup — the spoon handle gets hot by conduction.
200 — The students used 30 g of rock and copper but only 20 g of plastic. Explain how that difference in mass could affect which material appears to absorb the most thermal energy.
200 — Because thermal energy transferred depends on mass as well as material properties, using less plastic (20 g) means it could absorb less total energy than if 30 g had been used; this can make comparisons unfair.
200 — Two beakers of water at different temperatures are poured together and reach a single final temperature. What is this condition called?
200 — Thermal equilibrium.
300 — Which word describes the transfer of heat by direct contact between objects?
300 — Conduction.
300 — Describe a real-world example of convection (include why convection happens in that example).
300 — Example answer: Boiling water — hotter water rises and cooler water sinks, creating currents that transfer heat (because warmer fluid is less dense). 300 (alternate) — Convection happens because warmer fluid becomes less dense and rises while cooler fluid sinks.
. 300 — When copper metal is added to hot water, through which method is thermal energy primarily transferred between the copper and the water?
300 — Conduction.
300 — A student places 100°C water and 80°C water together inside one system. Predict whether the final temperature will be closer to 100°C or 80°C and explain why.
300 — The final temperature will be between 100°C and 80°C and closer toward the middle; the exact value depends on masses and specific heats, but energy is transferred until the two waters reach the same temperature (between 80°C and 100°C)
400 — Which form of heat transfer from the sun reaches Earth through empty space?
400 — Radiation.
400 — Peter took food out of a refrigerator and measured its temperature every few minutes. Describe the expected temperature change of the food and why.
400 — The cold food will gain thermal energy from the warmer air and increase in temperature until it is about the same temperature as the air (it warms up).
400 — A set of data shows water at 90°C cooling faster when a rock is added than when plastic is added. What does this tell you about the rock’s ability to absorb or transfer thermal energy compared to the plastic?
400 — The rock absorbs more thermal energy from the water (it has a higher capacity or conducts heat differently), causing a larger temperature drop in the water.
400 — Define thermal equilibrium and describe what happens to thermal energy between two objects that reach it.
. 400 — Thermal equilibrium is when two objects in contact reach the same temperature; thermal energy stops flowing between them because there is no temperature difference.
500 — Explain how particle motion (kinetic energy) differs between a hot substance and a cold substance.
500 — Hot substances have particles with greater average kinetic energy (particles move faster) than cold substances.
500 — A lamp makes a lampshade hot while the air near it also warms. Identify which method(s) of heat transfer are acting and explain your answer.
500 — The lamp shining on the lampshade warms it by radiation (light energy). The lampshade then warms nearby air and surfaces by conduction (direct contact) and possibly convection (warm air rising). Common concise answer: radiation to shade, conduction through shade material, convection to surrounding air.
500 — Design a simple procedure (3–4 steps) to test which mug (ceramic or thermos) keeps coffee hotter longer. Include one control and one variable.
500 — Example procedure:
500 — Luis mixed liquids of different temperatures and found the final temperature was lower than expected. Give two plausible reasons (based on heat transfer) why the final temperature could be lower than his theoretical value.
500 — Possible reasons: