( again ( , ( ( the ( valence electrons ) ) ( ( ( are ( less strongly ) ) ( ( shared even ) ( in ( ( metallic bonding ) ( between ( mercury atoms ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB again)) (, ,) (NP (DT the) (JJ valence) (NNS electrons)) (VP (VBP are) (ADVP (RBR less) (RB strongly)) (VP (VBN shared) (ADVP (RB even)) (PP (IN in) (NP (NP (JJ metallic) (NN bonding)) (PP (IN between) (NP (NN mercury) (NNS atoms))))))) (. .)))
again, the valence electrons are less strongly shared even in metallic bonding between mercury atoms.
(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)))))))) (. .)))