A sealed balloon of negligible mass rises in air if the gas inside it is less dense than air. The table gives data for some gases at room temperature and pressure.
| Gas | Density in g dm−3\mathrm{g\,dm^{-3}}gdm−3 | Flammable? |
|---|---|---|
| air | 1.20 | no |
| hydrogen | 0.083 | yes |
| helium | 0.17 | no |
| neon | 0.83 | no |
| argon | 1.66 | no |
Which gases would make the balloon rise and are also safe to use near a flame?
helium and neon only
helium only
hydrogen and helium only
helium, neon and argon only
44 exam-style questions on Edexcel GCSE Chemistry 7.3 Group 0, covering 7.3.1 The noble gases. Each one has a worked solution and a mark scheme showing where the marks go.