Methane, CH4\mathrm{CH_{4}}CH4, water, H2O\mathrm{H_{2}O}H2O, and carbon dioxide, CO2\mathrm{CO_{2}}CO2, are all made of small molecules containing covalent bonds.
The electronic configurations are: hydrogen 1, carbon 2.4, oxygen 2.6.
The structure of water can be written as H-O-H, where each line represents a covalent bond. Give one piece of information shown by a dot-and-cross diagram of water that is not shown by H-O-H.
Compare the covalent bonding in molecules of methane, water and carbon dioxide. You should use the electronic configurations in your answer.
Calculate the total number of atoms in 2.2 g of carbon dioxide. Relative atomic masses: C = 12, O = 16. Avogadro constant = 6.02 × 1023 per mol
53 exam-style questions on Edexcel GCSE Chemistry 2.4 Covalent bonding, covering 2.4.1 Covalent bonding and simple molecules. Each one has a worked solution and a mark scheme showing where the marks go.