' The atom was named before it was split.
( ' ( ( The atom ) ( ( was ( named ( before ( it ( was split ) ) ) ) ) . ) ) )
(ROOT (S ('' ') (NP (DT The) (NN atom)) (VP (VBD was) (VP (VBN named) (SBAR (IN before) (S (NP (PRP it)) (VP (VBD was) (VP (VBN split))))))) (. .)))
After the splitting of the atom, atoms were renamed to a word which signified "easily split".
( ( After ( ( the splitting ) ( of ( the atom ) ) ) ) ( , ( atoms ( ( were ( renamed ( to ( ( a word ) ( which ( signified ( `` ( easily ( split '' ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN After) (NP (NP (DT the) (NN splitting)) (PP (IN of) (NP (DT the) (NN atom))))) (, ,) (NP (NNS atoms)) (VP (VBD were) (VP (VBN renamed) (PP (TO to) (NP (NP (DT a) (NN word)) (SBAR (WHNP (WDT which)) (S (VP (VBD signified) (ADJP (`` ``) (RB easily) (VBN split) ('' ''))))))))) (. .)))