( ( ( Carbon dioxide ) ( -LRB- ( ( chemical ( formula CO2 ) ) -RRB- ) ) ) ( ( is ( ( a ( ( naturally occurring ) ( chemical compound ) ) ) ( composed ( of ( ( two ( oxygen atoms ) ) ( ( ( each covalently ) double ) ( bonded ( to ( a ( single ( carbon atom ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Carbon) (NN dioxide)) (PRN (-LRB- -LRB-) (NP (JJ chemical) (NN formula) (NN CO2)) (-RRB- -RRB-))) (VP (VBZ is) (NP (NP (DT a) (ADJP (RB naturally) (VBG occurring)) (NN chemical) (NN compound)) (VP (VBN composed) (PP (IN of) (NP (NP (CD two) (NN oxygen) (NNS atoms)) (VP (ADVP (NP (DT each) (NN covalently)) (RB double)) (VBN bonded) (PP (TO to) (NP (DT a) (JJ single) (NN carbon) (NN atom))))))))) (. .)))
Carbon dioxide (chemical formula CO2) is a naturally occurring chemical compound composed of two oxygen atoms each covalently double bonded to a single carbon atom.
(ROOT (S (NP (NNP Carbon) (NN dioxide) (NNS molecules)) (VP (VBP consist) (PP (IN of) (NP (NP (DT a) (JJ central) (NN carbon) (NN atom)) (VP (VBN bonded) (PP (TO to) (NP (CD two) (NN oxygen) (NNS atoms))))))) (. .)))