‘The anomalies explained’ considers why water behaves differently from most other liquids and why this is so important chemically, biologically, and environmentally. Ice contracts on melting; a normal liquid expands. Below 4°C liquid water contracts on heating; a normal liquid expands. Between the melting point and 46°C, water’s compressibility falls as temperature increases; for a normal liquid it increases. Water’s viscosity at or below about 30°C falls as pressure increases from 1 to 1,000 atmospheres; it increases for a normal liquid. The local intermolecular geometry is responsible for these ‘anomalies’. The electrical properties of the water molecule result in other distinct properties: water is a very powerful solvent and it conducts electricity.