( ( ( The structure ) ( of ( the ( Periodic Table ) ) ) ) ( ( is ( shown ( to ( reflect ( ( the ( energy levels ) ) ( of ( electrons ( in ( the atom ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN structure)) (PP (IN of) (NP (DT the) (NNP Periodic) (NNP Table)))) (VP (VBZ is) (VP (VBN shown) (S (VP (TO to) (VP (VB reflect) (NP (NP (DT the) (NN energy) (NNS levels)) (PP (IN of) (NP (NP (NNS electrons)) (PP (IN in) (NP (DT the) (NN atom))))))))))) (. .)))
The structure of the Periodic Table is shown to reflect the energy levels of electrons in the atom.
(ROOT (S (NP (NP (NNS Electrons)) (PP (IN in) (NP (NP (JJ successive) (NNS atoms)) (PP (IN on) (NP (DT the) (JJ periodic) (NN table)))))) (VP (VBP tend) (S (VP (TO to) (VP (VB fill) (NP (JJ low-energy) (NNS orbitals)) (ADVP (RB first)))))) (. .)))