( Oxygen ( ( is ( ( the ( ( most plentiful ) element ) ) ( on Earth ) ) ) . ) )
(ROOT (S (NP (NNP Oxygen)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RBS most) (JJ plentiful)) (NN element)) (PP (IN on) (NP (NNP Earth))))) (. .)))
Oxygen is the most plentiful element on Earth.
(ROOT (S (NP (NNP Oxygen)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (DT the) (JJ second) (ADJP (RBS most) (JJ electronegative)) (NN element))))) (. .)))