Properties of water equal to that of the hydrogen ion (), which gives a pH of 7 at 25 °C. Action of water on rock over long periods of time typically leads to weathering and water erosion, physical processes that convert solid rocks and minerals into soil and sediment, but under some conditions chemical reactions with water occur as well, resulting in metasomatism or mineral hydration, a type of chemical alteration of a rock which produces clay minerals. It also occurs when Portland cement hardens. Water ice can form clathrate compounds, known as clathrate hydrates, with a variety of small molecules that can
Sharing the water of the Ganges that India is drawing excessive water and the amount allocated to Bangladesh is unjust and insufficient. India in turn complains that the water allocated to Bangladesh leaves it with less water than necessary for the functioning of the Kolkata Port and the National Thermal Power Corporation in Farakka. Other critics have also stressed environmental reasons for India to reconsider its drawing of water at Farraka. Alarming increases in deforestation and erosion at the upper levels of the Ganges river increases the deposition of silt at the lower level, which is already measured at 2 million tonnes annually, along with increased