A molecule contains one carbon atom joined to two oxygen atoms. Which bonding arrangement gives every atom a full outer shell?
two C=O\mathrm{C=O}C=O double bonds
one C=O\mathrm{C=O}C=O double bond and one C−O\mathrm{C-O}C−O single bond
an ionic bond to each oxygen
two C−O\mathrm{C-O}C−O single bonds
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.