( ( ( Chemistry - ) ( ( Atoms ( , ( Reactions ( & ( Inorganic Molecules ) ) ) ) ) 3 ) ) . )
(ROOT (NP (NP (NNP Chemistry)) (: -) (NP (NP (NNP Atoms) (, ,) (NNP Reactions) (CC &) (NNP Inorganic) (NNP Molecules)) (NP (CD 3))) (. .)))
Chemistry- Atoms, Reactions &amp; Inorganic Molecules 3.
(ROOT (S (ADVP (RB Replace)) (NP (NP (DT another)) (PP (IN in) (NP (DT a) (NN molecule)))) (VP (VBZ happens) (PP (TO to) (NP (NNS atoms))) (PP (IN during) (NP (DT a) (NN substitution) (NN reaction)))) (. .)))
Replace another in a molecule happens to atoms during a substitution reaction.