<P> Ice molecules can exhibit eighteen or more different phases ( packing geometries ) that depend on temperature and pressure . When water is cooled rapidly ( quenching ) , up to three different types of amorphous ice can form depending on the history of its pressure and temperature . When cooled slowly correlated proton tunneling occurs below 20 K ( − 253 ° C ) giving rise to macroscopic quantum phenomena . Virtually all the ice on Earth 's surface and in its atmosphere is of a hexagonal crystalline structure denoted as ice I ( spoken as `` ice one h '' ) with minute traces of cubic ice denoted as ice I . The most common phase transition to ice I occurs when liquid water is cooled below 7002273149999999999 ♠ 0 ° C ( 7002273149999999999 ♠ 273.15 K , 7002273149999999999 ♠ 32 ° F ) at standard atmospheric pressure . It may also be deposited directly by water vapor , as happens in the formation of frost . The transition from ice to water is melting and from ice directly to water vapor is sublimation . </P>
<P> Ice molecules can exhibit eighteen or more different phases ( packing geometries ) that depend on temperature and pressure . When water is cooled rapidly ( quenching ) , up to three different types of amorphous ice can form depending on the history of its pressure and temperature . When cooled slowly correlated proton tunneling occurs below 20 K ( − 253 ° C ) giving rise to macroscopic quantum phenomena . Virtually all the ice on Earth 's surface and in its atmosphere is of a hexagonal crystalline structure denoted as ice I ( spoken as `` ice one h '' ) with minute traces of cubic ice denoted as ice I . The most common phase transition to ice I occurs when liquid water is cooled below 7002273149999999999 ♠ 0 ° C ( 7002273149999999999 ♠ 273.15 K , 7002273149999999999 ♠ 32 ° F ) at standard atmospheric pressure . It may also be deposited directly by water vapor , as happens in the formation of frost . The transition from ice to water is melting and from ice directly to water vapor is sublimation . </P>
at what temperature does water turn into ice in degree celsius
at what temperature does water turn into ice in degree celsius
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