( ( A ( ( highly reactive ) element ) ) ( ( ( ( ( reacts ( ( ( very easily ) , ) ( maybe even ) ) ) violently ) , ) ( with ( lots ( of ( other ( ( elements or ) compounds ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (ADJP (RB highly) (JJ reactive)) (NN element)) (VP (VBZ reacts) (ADVP (ADVP (RB very) (RB easily)) (, ,) (ADVP (RB maybe) (RB even))) (ADVP (RB violently)) (, ,) (PP (IN with) (NP (NP (NNS lots)) (PP (IN of) (NP (JJ other) (NNS elements) (CC or) (NNS compounds)))))) (. .)))
A highly reactive element reacts very easily, maybe even violently, with lots of other elements or compounds.
(ROOT (S (NP (JJ Reactive) (NNS elements)) (VP (VBP are) (ADJP (JJ able) (S (VP (TO to) (VP (VB combine) (ADVP (RBR more) (RB easily)) (PP (IN with) (NP (JJ other) (NNS elements)))))))) (. .)))