The subject involves the application of chemistry principles to solve problems related to the understanding of our Earth and environment. Broad topics include the origin of the Earth and solar system, the distribution of elements in minerals, rocks, soil and water, common reactions on the surface of the Earth, the deposition of mineral deposits, the global cycling of elements, the evolution of the Earth and oceans. Specific examples of subjects covered are nucleosynthesis and the iron core of the Earth, ionic substitution in crystals and fluorinated water, radiometric dating of meteorites and the age of the Earth, redox reactions and acid sulphate soil formation, origin of photosynthesis and banded iron deposition, regolith formation in tropical environments, supergene processes and copper mineralisation, stable isotope fractionation and glacial-interglacial transitions, chemical variation of the ocean and the evolution of life, the fate of fossil fuel emissions to the atmosphere, pollution traces in the environment, chemistry and ethics of waste disposal.