isms ▁of ▁transformation ▁than ▁any ▁other ▁science . ▁ ▁Appro ach ▁ ▁Although ▁both ▁physics ▁and ▁chem istry ▁are ▁concerned ▁with ▁matter ▁and ▁its ▁interaction ▁with ▁energy , ▁the ▁two ▁discipl ines ▁differ ▁in ▁approach . ▁In ▁physics , ▁it ▁is ▁typical ▁to ▁abstract ▁from ▁the ▁specific ▁type ▁of ▁matter , ▁and ▁to ▁focus ▁on ▁the ▁common ▁properties ▁of ▁many ▁different ▁materials . ▁ ▁In ▁opt ics , ▁for ▁example , ▁materials ▁are ▁character ized ▁by ▁their ▁index ▁of ▁ref raction , ▁and ▁materials ▁with ▁the ▁same ▁index ▁of ▁ref raction ▁will ▁have ▁identical ▁properties . ▁Chem istry , ▁on ▁the ▁other ▁hand , ▁focus es ▁on ▁what ▁comp ounds ▁are ▁present ▁in ▁a ▁sample , ▁and ▁expl ores ▁how ▁changing ▁the ▁structure ▁of ▁mole cules ▁will ▁change ▁their ▁react ivity ▁and ▁their ▁physical ▁properties . ▁ ▁The ▁two ▁sciences ▁differ ▁in ▁the ▁role ▁that ▁theory ▁plays ▁within ▁the ▁discipline . ▁Physics ▁can ▁be ▁divided ▁into ▁experimental ▁and ▁theoretical ▁physics . ▁Histor ically , ▁theoretical ▁physics ▁has ▁correctly ▁predicted ▁phen omena ▁that ▁were ▁out ▁of ▁experimental ▁reach ▁at ▁the ▁time , ▁and ▁could ▁be ▁verified ▁only ▁after ▁experimental ▁techniques ▁caught ▁up . ▁ ▁In ▁chem istry , ▁the ▁role ▁of ▁theory ▁histor ically ▁has ▁been ▁a ▁ret ros pective ▁one , ▁summar izing ▁experimental ▁data ▁and ▁predict ing ▁the ▁outcome ▁of ▁similar ▁experiments . ▁ ▁However , ▁with ▁the ▁increasing ▁power ▁of ▁computational ▁methods ▁in ▁chem istry , ▁it ▁has ▁become ▁possible ▁to ▁predict ▁whether ▁a ▁hypoth et ical ▁comp ound ▁is ▁stable