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
Nonresidential water use in the U.S. their associated benchmarks) in order to assess their success in achieving water use efficiency goals. A “metric” (or “performance indicator”) is a unit of measure (based on a formula) that can be used to calculate the rate of water use during a given period of time (and at a given level of data aggregation). A “benchmark” is a particular (numerical) value of a metric that denotes a specific level of performance, such as a water-use efficiency target. When quantifying water use in the CII sector, the total volume of consumption (over any given time interval) at any given CII facility