Gases at Work
Match each gas to its everyday job.
What this lesson covers
Why it matters
The gases in the air are not just for breathing — they have day jobs! One fills fizzy drinks, one glows in signs, one lifts balloons and one keeps hospital patients alive.
Predict first
Which gas is used inside fire extinguishers to put out flames?
Carbon dioxide is used in fire extinguishers. It is heavier than air and does not burn, so it blankets the fire and cuts off the oxygen, putting the flames out.
- Oxygen
- Carbon dioxide — correct
- More air
- Hydrogen
What you do
Match each everyday job to the gas that does it. Drag each use into the correct gas bin.
Check yourself
Why does carbon dioxide put out a fire?
Carbon dioxide does not burn and is heavier than air, so it settles over a fire like a blanket and keeps oxygen away, so the flames die.
Which gas is used in glowing advertising signs?
Neon, a noble gas, glows with a bright orange-red light when electricity passes through it, which is why it is used in colourful signs.
Why is helium used to fill party balloons that float upward?
Helium is a very light noble gas — lighter than air — so a balloon filled with it is pulled upward and floats. It is also safe because it does not burn.
- It is heavier than air and does not burn, so it smothers the flames — correct
- It burns up all the smoke
- It is lighter than air and floats away
- It adds extra oxygen to the fire
- Neon (a noble gas) — correct
- Oxygen
- Carbon dioxide
- Water vapour
- It is lighter than air, so the balloon rises — correct
- It is heavier than air, so the balloon sinks
- It catches fire easily and lifts the balloon
- It is the same weight as air