( ( ( ( ( ( Classical theory ) ( had ( been ( unable ( to ( explain ( ( the stability ) ( of ( ( the ( nuclear model ) ) ( of ( the Atom ) ) ) ) ) ) ) ) ) ) ) , ) but ) ( Bohr ( ( solved ( the problem ) ) ( by ( ( ( postulating ( that ( Electron ( s ( move ( in ( ( restricted orbits ) ( around ( ( the ( atom 's ) ) nucleus ) ) ) ) ) ) ) ) ) and ) ( explaining ( how ( ( the atom ) ( ( ( emits and ) absorbs ) Energy ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Classical) (NN theory)) (VP (VBD had) (VP (VBN been) (ADJP (JJ unable) (S (VP (TO to) (VP (VB explain) (NP (NP (DT the) (NN stability)) (PP (IN of) (NP (NP (DT the) (JJ nuclear) (NN model)) (PP (IN of) (NP (DT the) (NNP Atom))))))))))))) (, ,) (CC but) (S (NP (NNP Bohr)) (VP (VBD solved) (NP (DT the) (NN problem)) (PP (IN by) (S (VP (VP (VBG postulating) (SBAR (IN that) (S (NP (NNP Electron)) (VP (VBZ s) (NP (NP (NN move)) (PP (IN in) (NP (NP (VBN restricted) (NNS orbits)) (PP (IN around) (NP (NP (DT the) (NN atom) (POS 's)) (NN nucleus)))))))))) (CC and) (VP (VBG explaining) (SBAR (WHADVP (WRB how)) (S (NP (DT the) (NN atom)) (VP (VBZ emits) (CC and) (VBZ absorbs) (NP (NNP Energy))))))))))) (. .)))
Classical theory had been unable to explain the stability of the nuclear model of the Atom , but Bohr solved the problem by postulating that Electron s move in restricted orbits around the atom's nucleus and explaining how the atom emits and absorbs Energy .
(ROOT (S (NP (DT An) (NN electron)) (VP (VBZ moves) (PP (TO to) (NP (NP (DT a) (NN shell)) (ADVP (RB farther) (PP (IN from) (NP (DT the) (NN nucleus)))))) (SBAR (IN after) (S (NP (PRP it)) (VP (VBZ absorbs) (NP (NN energy)))))) (. .)))