Geochemistry is the science that Deals with Chemical composition of earth and other planets,chemical processes ,cycles,reactions,that governs the composition of rock and soils, and temporal and spatial changes in these controlling factors. Thus it explains the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of this science extends beyond the Earth, encompassing the entire Solar System and has made important contributions to the understanding of a number of processes including mantle convection, the formation of planets and the origins of granite and basalt.