7th grade · Science · Unit 5 of 18
Moving Heat
Conduction, convection, radiation
What your child practices
How heat is transmitted by conduction, convection and radiation, how the Sun's radiation heats different surfaces, and technologies such as insulation and double-pane windows that reduce heat loss.
Texas Essential Knowledge and Skills (TEKS) teks student expectation: 7.8(A) · conduction, convection and radiation
How we explain it
Children can open this short lesson before they practice.
- Conduction moves heat through touching materials, like a hot pan handle.
- Convection moves heat through flowing liquids or gases, like warm air rising.
- Radiation moves heat as rays with no material needed, like sunlight. Insulators slow heat loss.
Example: You feel warm sitting near a fire without touching it. Which kind of heat transfer is it? You aren’t touching anything hot. The heat travels as rays through the air. Answer: radiation
Moving Heat in Texas
In the Texas Essential Knowledge and Skills (TEKS), this is unit 5 of 18 in 7th grade Science, after Motion, Forces & Newton’s Laws and before Heat & Particles.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Texas Education Agency (TEA)
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Better insulation in homes reduces heat loss. What is one environmental benefit?
- Less energy is needed for heating, so fewer greenhouse gases are released
- Insulation removes carbon from the air
- Homes make their own heat
- Homes need more fuel
Less energy is needed for heating, so fewer greenhouse gases are released
Hint: If heating uses fossil fuels, using less reduces emissions.
Question 2
Which surface absorbs the most radiation from the Sun?
- a mirror
- dark pavement
- a white roof
- fresh snow
dark pavement
Hint: Dark surfaces absorb more. Light and shiny ones reflect more.
Question 3
How does energy from the Sun reach Earth?
- radiation
- conduction
- convection
radiation
Hint: Space is almost empty, so heat there can only travel as radiation.
Question 4
Which action would NOT reduce heat loss from a house in winter?
- adding attic insulation
- installing double-pane windows
- sealing gaps around doors
- opening windows to let in fresh air for hours
opening windows to let in fresh air for hours
Hint: Open windows let warm air escape and cold air in.
Question 5
Conduction, convection or radiation? Sort each example.
Sort into: 🥄 conduction · 🌬️ convection · ☀️ radiation
- ☀️warmth from the Sun on your face
- 🍲water circulating in a boiling pot
- 🔥warmth from a campfire felt at a distance
- 🥄a metal spoon warming in hot soup
- ♨️warm air rising from a radiator
- 🏖️bare feet heated by hot sand
🥄 conduction: a metal spoon warming in hot soup, bare feet heated by hot sand · 🌬️ convection: water circulating in a boiling pot, warm air rising from a radiator · ☀️ radiation: warmth from the Sun on your face, warmth from a campfire felt at a distance
Hint: Conduction: heat passes through direct contact. Convection: heat is carried by moving liquid or gas. Radiation: heat travels as waves, even through empty space.
Question 6
During the day near a big lake, the land warms faster than the water. What happens to the air over the land?
- It stops moving
- It warms and rises, and cooler air from the lake moves in
- It cools and sinks
- It changes into water
It warms and rises, and cooler air from the lake moves in
Hint: This convection current is called a lake or sea breeze.