on ▁atoms ▁to ▁yield ▁. ▁these ▁arg on ▁atoms ▁can ▁be ▁subst it uted ▁by ▁numbers ▁of ▁k rypt on ▁or ▁x en on ▁atoms ▁to ▁yield ▁even ▁more ▁mixed ▁noble ▁gas ▁mole cules . ▁With ▁y tt rium , ▁Y O + ▁b onds ▁six ▁arg on ▁atoms , ▁and ▁these ▁too ▁can ▁be ▁subst it uted ▁by ▁varying ▁numbers ▁of ▁k rypt on ▁or ▁x en on ▁atoms . ▁ ▁In ▁the ▁case ▁of ▁transition ▁metal ▁mon ox ides , ▁Sc O , ▁Ti O ▁and ▁V O ▁do ▁not ▁form ▁a ▁mole c ule ▁with ▁one ▁arg on ▁atom . ▁However ▁Cr O , ▁M n O , ▁Fe O , ▁Co O ▁and ▁Ni O ▁can ▁each ▁coordinate ▁one ▁arg on ▁atom ▁in ▁a ▁solid ▁arg on ▁matrix . ▁The ▁metal ▁mon ox ide ▁mole cules ▁can ▁be ▁produced ▁by ▁las er ▁ab lation ▁of ▁the ▁metal ▁tri ox ide , ▁followed ▁by ▁cond ens ation ▁on ▁solid ▁arg on . ▁Ar Cr O ▁absor bs ▁at ▁ 8 4 6 . 3   cm − 1 , ▁Ar M n O ▁at ▁ 8 3 3 . 1 , ▁Ar Fe O ▁at ▁ 8 7 2 . 8 , ▁Ar Co O ▁at ▁ 8 4 6 . 2 , ▁Ar 5 8 N i O ▁at ▁ 8 2 5 . 7 ▁and ▁Ar 6 0 N i O ▁at ▁ 8 2 2 . 8   cm − 1 . ▁All ▁these ▁mole cules ▁are