Ahmad Ghozlan · Science · Grade 7 · Heat Transfer & Temperature
🔥 Engage
📖 Concepts
🌡️ Thermometers
🔩 Conduction
🌊 Convection
☀️ Radiation
⚖️ Compare
✏️ Practice
📊 Submit
E1 · Engage
Hot or High Temperature?
These two words sound the same — but in science they mean very different things. Let's find out why!
🤔 Think about this: A small cup of boiling water and a large swimming pool at 30°C.
Which has more heat? Which has a higher temperature? Are they the same thing?
AThe boiling water has more heat AND higher temperature
BThe boiling water has higher temperature, but the pool has more total heat
CThey are the same — heat and temperature mean the same thing
E2 · Concepts
Heat vs Temperature
Two completely different quantities — learn them both!
🔥
HEAT (Q)
Heat is a form of energy that flows from a hot object to a cold one. It depends on the number of particles AND their speed.
Unit: Joule (J)
🌡️
TEMPERATURE (T)
Temperature measures how fast the particles of an object are moving on average. Higher temperature = faster particles.
Unit: degree Celsius (°C)
🔑 Key Difference
• Heat = total energy → depends on how much material there is
• Temperature = average particle energy → does NOT depend on amount
• A small spark and a large fire can reach the same temperature, but the fire has FAR more heat energy.
🎯 Quick Game — Is it Heat or Temperature?
E3 · Read the Thermometer
Thermometer Readings 🌡️
Read each thermometer carefully. Give the value and choose the correct unit. Look at where the liquid level is and count the scale carefully!
📏 How to read: Find where the top of the liquid is. Read the number on the scale at that exact level. Each small line between numbers = 2°C. Give your answer as a number, then choose °C.
E3 · Heat Transfer
🔩 Conduction
Heat travels through a solid material by passing energy from particle to particle — like dominoes falling! Watch the animation below.
CONDUCTION — Metal Rod
Click to apply heat to the left end
What you see:
🔴 The nails (wax-attached) fall off one by one as heat reaches each position.
➡️ Heat travels from hot end → cold end through the solid.
🏠 Examples: metal spoon in hot soup, iron handle heating up, heat spreading through a wall.
Conduction Question
Heat travels through solids because:
AHot particles move from one place to another carrying energy
BParticles vibrate and pass energy to their neighbours without moving
CHeat rays travel through the solid material
E3 · Heat Transfer
🌊 Convection
Heat travels through liquids and gases by the actual movement of the fluid itself — hot fluid rises, cool fluid sinks, creating a current!
CONVECTION — Fluid Current
Click to heat the bottom
What happens:
🔴 Hot fluid at the bottom expands → becomes lighter → rises
🔵 Cool fluid at the top contracts → becomes heavier → sinks
🌀 This creates a convection current — a circular loop of moving fluid
🏠 Examples: boiling water in a pot, sea breezes, heating a room with a radiator
Convection Question
In convection, why does heated fluid rise?
AIt becomes heavier so it floats up
BIt expands and becomes less dense (lighter) so it rises
CHeat always moves upward
E3 · Heat Transfer
☀️ Radiation
Heat travels as invisible waves — no material needed at all! This is how the Sun heats the Earth across empty space.
RADIATION — Heat Waves
Click to start radiation
Key facts:
☀️ Radiation travels as infrared waves — a type of electromagnetic wave
🚀 It can travel through empty space (vacuum) — no particles needed
⚫ Dark, rough surfaces absorb AND emit radiation better
⚪ Shiny, light surfaces reflect radiation — they absorb and emit less
🏠 Examples: Sun heating Earth, sitting near a fire, microwave oven
Radiation Question
Which surface absorbs the most radiation?
AShiny silver surface
BWhite smooth surface
CDull black surface
E4 · Compare
⚖️ All Three Side by Side
Tap each panel to see the animation for each method. Then complete the comparison table!
🔩 CONDUCTION
Solids only
🌊 CONVECTION
Liquids & gases
☀️ RADIATION
No material needed
🎯 Match Each Description to the Correct Method
E4 · Practice
✏️ Test Your Knowledge
Five questions mixing all the topics from today's lab.
Question 1 · Heat vs Temperature
A student has a small cup of water at 80°C and a large bathtub of water at 40°C. Which statement is TRUE?
AThe cup has more heat because it is hotter
BThe bathtub has more heat even though it is cooler
CThe cup and bathtub have the same heat because heat = temperature
Question 2 · Units
A student measures the temperature of boiling water. She records: "The temperature is 100 ___". What is the correct unit?
AJoules (J)
BDegrees Celsius (°C)
CMetres (m)
Question 3 · True or False
The Sun heats the Earth by convection through space.
Question 4 · Identify the Method
When you hold a metal spoon in hot soup, the handle gradually gets hot even though it is not in the soup. This is an example of:
AConvection
BRadiation
CConduction
Question 5 · Open Question · AI Tutor 🤖
A thermos flask (vacuum flask) keeps hot drinks hot for a long time. Explain how it reduces heat loss by all three methods of heat transfer. Hint: think about what each layer of the flask does.
E5 · Submit
📊 Submit Your Work
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Your Score
Ahmad reviews your thermometer readings and open answer in the next class.