( ( 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 (JJ Metallic) (NNS bonds)) (VP (VBP hold) (PRT (RP together)) (NP (NP (JJ positive) (NN metal) (NNS ions)) (CC and) (NP (PRP$ their) (JJ valence) (NNS electrons)))) (. .)))