Ice Ih
Ice Ih (pronounced: ice one h, also known as ice one) is the hexagonal crystal form of ordinary ice, or frozen water. Virtually all ice in the biosphere is ice Ih, with the exception only of a small amount of ice Ic which is occasionally present in the upper atmosphere. Ice Ih exhibits many peculiar properties which are relevant to the existence of life and regulation of global climate.
Ice Ih is stable down to −200 °C (73 K; −328 °F) and can exist at pressures up to 0.2 GPa. The crystal structure is characterized by hexagonal symmetry and near tetrahedral bonding angles.
Read more about Ice Ih: Physical Properties, Crystal Structure, Proton Disorder
Famous quotes containing the word ice:
“I also heard the whooping of the ice in the pond, my great bed-fellow in that part of Concord, as if it were restless in its bed and would fain turn over, were troubled with flatulency and bad dreams; or I was waked by the cracking of the ground by the frost, as if some one had driven a team against my door, and in the morning would find a crack in the earth a quarter of a mile long and a third of an inch wide.”
—Henry David Thoreau (1817–1862)