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
Water politics in the Middle East the other states through which the Nile also runs. The countries which rely upon the Tigris-Euphrates water system remain at the first stage of claiming their rights to water. However, the key player in terms of water politics in this area is Turkey, who Allan reports as having "gone a substantial way to[wards]… what it regards as its water rights by its construction programs on the Euphrates without having them recognized by downstream Syria and Iraq". This refers to the dams built by Turkey from the 1970s, partially funded by World Bank loans. The Syria-Lebanon-Palestine boundary was a product of