( Thus ( , ( ( ( the ( planetary model ) ) ( of ( the atom ) ) ) ( ( was ( discarded ( in ( ( favor ( of one ) ) ( that ( ( ( described ( atomic ( orbital zones ) ) ) ( around ( the nucleus ) ) ) ( where ( ( a ( given electron ) ) ( is ( most ( likely ( to ( be observed ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Thus)) (, ,) (NP (NP (DT the) (JJ planetary) (NN model)) (PP (IN of) (NP (DT the) (NN atom)))) (VP (VBD was) (VP (VBN discarded) (PP (IN in) (NP (NP (NN favor)) (PP (IN of) (NP (CD one))) (SBAR (WHNP (WDT that)) (S (VP (VBD described) (NP (JJ atomic) (JJ orbital) (NNS zones)) (PP (IN around) (NP (DT the) (NN nucleus))) (SBAR (WHADVP (WRB where)) (S (NP (DT a) (VBN given) (NN electron)) (VP (VBZ is) (ADJP (RBS most) (JJ likely) (S (VP (TO to) (VP (VB be) (ADJP (JJ observed)))))))))))))))) (. .)))
Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.
(ROOT (S (NP (DT The) (NN orbital)) (VP (VBZ is) (NP (NP (DT the) (NN area)) (SBAR (WHADVP (WRB where)) (S (NP (DT an) (NN electron)) (VP (VBZ is) (ADJP (RBS most) (JJ likely) (S (VP (TO to) (VP (VB be) (VP (VBN found))))))))))) (. .)))