( ( of ( ( valence electrons ) ( is 2 ) ) ) ( , ( we ( ( predict ( a ( METALLIC BOND ) ) ) . ) ) ) )
(ROOT (S (PP (IN of) (NP (NP (JJ valence) (NNS electrons)) (SBAR (S (VP (VBZ is) (NP (CD 2))))))) (, ,) (NP (PRP we)) (VP (VBP predict) (NP (DT a) (NNP METALLIC) (NN BOND))) (. .)))
of valence electrons is 2, we predict a METALLIC BOND .
(ROOT (S (NP (DT A) (JJ metallic) (NN bond)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN attraction)) (PP (IN between) (NP (NP (DT a) (JJ positive) (NN metal) (NN ion)) (CC and) (NP (JJ valence) (NNS electrons)))))))) (. .)))