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 privatization in the United States subsidiary of the French company Suez Environment, American Water, and Siemens from Germany which acquired US Filter Corps from French Veolia Environment and runs it under the Siemens name. In "Water Privatization Trends in the United States: Human Rights, National Security, and Public Stewardship", Craig Anthony Arnold argues that there is a lack of incentive for private water companies to carry out improvements or maintenance in public water systems that will have lasting benefits beyond their contract term. There are other criticisms of privatization outside the classic argument of "public" versus "private", the most of fundamental example being the claim