Search
Subjects and activities

Topic ladders · Physics

Air & Breathing

One topic, four rungs: from Classes 1–3 to Classes 11–12. Start at your own stage, or climb from the bottom. Every rung follows the same six steps: Notice, Guess, Try, Observe, Explain, Ask another question.

Print the family table: all four rungs side by side on one sheet, so everyone at home can find their own rung.

Choose your class stage

Rung 1 · Classes 1–3

Air Is All Around Us

Before you start: safety and help

For the grown-up who helps.

  • Safety: Simple and safe. Blow up balloons yourself and do not share them between mouths. Pick up burst balloon pieces at once: they are a choking risk for small children. Wipe up spilled water.

What you need

  • Empty plastic bottle, a clear glass, a dry tissue, balloon, paper, a bucket or deep bowl of water

Child steps

  1. Notice. Can you see air? How do you know it is there?
  2. Guess. Is the "empty" glass really empty? If we push it upside down into water, will a tissue inside get wet?
  3. Try. Push a dry tissue into the bottom of the glass. Push the glass straight down, upside down, into the water, then lift it straight out. Also wave paper to feel air, and let air out of a balloon a grown-up has blown up.
  4. Observe. Is the tissue still dry? Tilt the glass under water: what comes out? What evidence shows that air takes up space and can move?
  5. Explain. Tell someone that air is a real thing even though we cannot see it.
  6. Ask another question. What happens when we breathe air in and out?
For teachers
  • Learning aims: Understand that air is a real material that occupies space.
  • Key vocabulary: air, space, breathe, wind, bubbles.
  • Expected result: the tissue stays dry because the trapped air keeps the water out; tilting lets air escape as bubbles and water comes in.
  • Review: Children show one piece of evidence that air exists.

Rung 2 · Classes 4–7

Breathing and the Need for Air

Before you start: safety and help

For the grown-up or teacher who helps. Students: read it too, so you know the rules.

  • Safety: Keep exercise gentle. Skip the exercise part if the child is unwell, has asthma or another breathing or heart condition, or if a doctor has said to avoid exercise. Stop if they feel dizzy or breathless. Have water nearby.

What you need

  • Stopwatch or timer
  • A partner
  • Paper for recording

Student steps

  1. Notice. We breathe all the time. What happens when we exercise?
  2. Guess. Will your breathing rate be higher after exercise?
  3. Try. Sit quietly for two minutes. Your partner counts your breaths for one minute (one breath = in and out). Then do one minute of gentle exercise, like marching on the spot. Count again straight away, and once more after five minutes of rest.
  4. Observe. Record the numbers and compare.
  5. Explain. Why do you think breathing rate changes with exercise?
  6. Ask another question. What else changes when we exercise (heart rate, feeling warm)?
For teachers
  • Learning aims: Measure breathing rate; link increased breathing to the body's need for more oxygen, and to removing more carbon dioxide, during activity.
  • Key vocabulary: breathing rate, rest, exercise, oxygen, carbon dioxide, recovery.
  • Note: A partner counts because people breathe differently when they count their own breaths.
  • Review: Students show their results and give a simple explanation.

Rung 3 · Classes 8–10

Composition of Air and Respiration

Before you start: safety and help

For the grown-up or teacher who helps. Students: read it too, so you know the rules.

  • Safety: Lighting and handling the candle is a grown-up job, on a metal tray, away from curtains and paper, with water nearby. Jars get hot. For limewater: eye protection, blow gently out through the straw and never suck in, one straw per person, wash hands afterwards. Limewater comes from a school laboratory, not made at home.

What you need

  • For the grown-up or teacher demonstration: a short candle on a metal tray, 2–3 glass jars of different sizes, a stopwatch, matches, a bowl of water nearby
  • Optional, at school: limewater (from the school laboratory), a clean straw for each person, a test tube, eye protection
  • Notebook

Student steps

  1. Notice. Air is a mixture. We use part of it when we breathe and when things burn.
  2. Guess. What happens to a candle burning in a closed jar? Will it burn longer in a bigger jar? What gas do we breathe out?
  3. Try. Watch a grown-up place jars of different sizes over a lit candle and time how long it burns under each. At school, with eye protection on, blow gently through a straw into a little limewater.
  4. Observe. Record burning times and any change in the limewater.
  5. Explain. Link results to the oxygen available in each jar and to carbon dioxide in breathed-out air.
  6. Ask another question. How do plants affect the balance of gases in the air?
For teachers
  • Learning aims: Understand that air contains oxygen needed for burning and respiration, and that carbon dioxide is produced.
  • Key vocabulary: oxygen, carbon dioxide, nitrogen, respiration, combustion, limewater.
  • Air facts: dry air is about 78% nitrogen, 21% oxygen, 1% argon and 0.04% carbon dioxide. Breathed-out air has about 16% oxygen and 4% carbon dioxide, which turns limewater milky.
  • Common misconception: if the jar stands in water, the water rises after the flame goes out. This is mainly because the air heated by the flame cools and contracts, not because "the oxygen was used up". The candle also goes out while about 15% oxygen is still left. A bigger jar holds more air, so the candle burns longer: that part is a fair conclusion.
  • Review: Students explain the candle experiment and the role of oxygen, including what it does not show.

Rung 4 · Classes 11–12

Investigating Respiratory or Gas Exchange Questions

Before you start: safety and help

For the grown-up or teacher who helps. Students: read it too, so you know the rules.

  • Safety and ethics: Single-use or properly cleaned mouthpieces; no sharing. No breath-holding contests and no fast over-breathing (both can cause fainting). Consent from every participant (a parent's too if under 18); anyone can stop at any time. People with asthma or other conditions take part only if they choose and their doctor's advice allows. Data recorded without names.

What you need

  • Depends on investigation (spirometer or a simple lung-volume bell jar or bottle method, sensors, secondary data)

Student steps

  1. Notice. Gas exchange and breathing rate are regulated and can be affected by many factors.
  2. Guess / Hypothesise. Choose a focused, ethical question about breathing, lung volume, or gas exchange.
  3. Try. Design a safe investigation or analyse secondary data.
  4. Observe. Collect or extract quantitative data.
  5. Explain. Interpret results in the context of human physiology and discuss limitations.
  6. Ask another question. How do your findings relate to health, exercise physiology or environmental factors?
For teachers
  • Learning aims: Investigate a respiratory question ethically and quantitatively.
  • Review: Students present method, data, interpretation and evaluation.

Same spark, other subjects

Your heartbeat

Feel it, count it, graph it, and find out why it changes.

Already in the School Lab

These Lab pages practise the same ideas, with questions to check yourself.

Nothing on this page is saved or sent. Make it on paper, keep it with you.

ProLearners Assist