( ( The ( contaminated ( metal ions ) ) ) ( are ( bonded into ) ) )
(ROOT (S (NP (DT The) (JJ contaminated) (NN metal) (NNS ions)) (VP (VBP are) (VP (VBG bonded) (PP (IN into))))))
The contaminated metal ions are bonded into
(ROOT (S (NP (NP (DT The) (NN force)) (PP (IN of) (NP (NP (NN attraction)) (PP (IN between) (NP (NP (DT a) (ADJP (ADVP (RB positively)) (VBN charged)) (NN metal) (NN ion)) (CC and) (NP (NP (DT the) (JJ valence) (NNS electrons)) (SBAR (S (NP (PRP it)) (VP (VBZ shares) (PP (IN with) (NP (NP (JJ other) (NNS ions)) (PP (IN of) (NP (DT the) (NN metal)))))))))))))) (VP (VBZ is) (VP (VBN called) (S (NP (DT a) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NN metallic) (NN bond))))) (. .)))
The force of attraction between a positively charged metal ion and the valence electrons it shares with other ions of the metal is called a(n) metallic bond.