A party balloon contains 3.6 dm33.6\,\mathrm{dm^{3}}3.6dm3 of helium at room temperature and pressure.
How many helium atoms are in the balloon?
(1 mol of any gas occupies 24 dm324\,\mathrm{dm^{3}}24dm3 at room temperature and pressure; Avogadro constant = 6.02 × 1023 per mole)
4.52×10224.52\times10^{22}4.52×1022
9.03×10229.03\times10^{22}9.03×1022
1.81×10231.81\times10^{23}1.81×1023
2.17×10242.17\times10^{24}2.17×1024
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.