( ( Orbital-filling diagrams ) ( ( might ( ( ( ( ( be ( drawn ( for ( the ( whole atom ) ) ) ) ) , ) but ) usually ) ( just ( show ( the ( outer ( electron ( energy level ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Orbital-filling) (NNS diagrams)) (VP (MD might) (VP (VP (VB be) (VP (VBN drawn) (PP (IN for) (NP (DT the) (JJ whole) (NN atom))))) (, ,) (CC but) (ADVP (RB usually)) (VP (ADVP (RB just)) (VB show) (NP (DT the) (JJ outer) (NN electron) (NN energy) (NN level))))) (. .)))
Orbital-filling diagrams might be drawn for the whole atom, but usually just show the outer electron energy level.
(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)))))) (. .)))