Water

Ruwa wani fili ne na inorganic tare da dabarar sinadarai H2O. Yana da bayyananne, mara ɗanɗano, mara wari, [c] kuma kusan abu na sinadari mara launi. Ita ce babban abin da ke tattare da ruwa na duniya da kuma ruwan duk sanannun halittu masu rai (wanda yake aiki a matsayin mai narkewa. Yana da mahimmanci ga duk sanannun nau'ikan rayuwa, duk da rashin samar da makamashin abinci ko micronutrients. Tsarin sinadaransa, H2O, yana nuni da cewa kowanne daga cikin kwayoyin halittarsa yana dauke da iskar oxygen daya da kuma atom din hydrogen guda biyu, wadanda aka hada su ta hanyar covalent bond. Ana manne da zarra na hydrogen zuwa atom ɗin oxygen a kusurwar 104.45°. A cikin nau'in ruwa, H2O kuma ana kiransa "ruwa" a daidaitaccen zafin jiki da matsa lamba.

Saboda yanayin duniya yana kusa da wurin ruwa sau uku, ruwa yana wanzuwa a duniya a matsayin mai ƙarfi, ruwa, da iskar gas.[22] Yana haifar da hazo a cikin nau'in ruwan sama da kuma iska ta hanyar hazo. Gizagizai sun ƙunshi ɗigon ruwa da ƙanƙara da aka dakatar, yanayinsa mai ƙarfi. Lokacin da aka raba da kyau, ƙanƙara na crystalline na iya yin hazo ta hanyar dusar ƙanƙara. Yanayin gas na ruwa shine tururi ko tururin ruwa.