( Atoms ( ( can ( ( attract ( additional electrons ) ) ( if ( there ( is ( ( room ( for them ) ) ( in ( the ( valence ( energy level ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Atoms)) (VP (MD can) (VP (VB attract) (NP (JJ additional) (NNS electrons)) (SBAR (IN if) (S (NP (EX there)) (VP (VBZ is) (NP (NP (NN room)) (PP (IN for) (NP (PRP them))) (PP (IN in) (NP (DT the) (JJ valence) (NN energy) (NN level))))))))) (. .)))
Atoms can attract additional electrons if there is room for them in the valence energy level.
(ROOT (S (NP (NP (NNS Electrons)) (PP (IN in) (NP (NP (DT the) (JJ outer) (NN energy) (NN level)) (PP (IN of) (NP (DT an) (NN atom)))))) (VP (VBP are) (VP (VBN called) (NP (JJ valence) (NNS electrons)))) (. .)))