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 law in the United States decide the nature of the respective rights of public and private parties arising from the alteration of the hydrology of a watershed. It is important to recognize that there are both private and public 'rights' associated with the water, but that ownership of the water under common law is likened to claiming to "own" sunlight. Water must be legally appropriated before it is 'owned', and regulations on appropriation are typically controlled by government agencies and case laws. Who has domain over water is typically based on who owns the underlying soils, but Local, State and Federal regulations often limit the