( Ozone ( ( ( is ( ( O3 , ) ( ( three molecules ) ( of ( oxygen bonded ) ) ) ) ) together ) . ) )
(ROOT (S (NP (NN Ozone)) (VP (VBZ is) (NP (NP (NNP O3)) (, ,) (NP (NP (CD three) (NNS molecules)) (PP (IN of) (NP (NN oxygen) (NNS bonded))))) (ADVP (RB together))) (. .)))
Ozone is O3, three molecules of oxygen bonded together.
(ROOT (S (NP (CD Three) (NN oxygen) (NNS ions)) (VP (VBP make) (PRT (RP up)) (NP (DT an) (NN ozone) (NN molecule))) (. .)))