( ( Metallic bonds ) ( ( form ( between ( atoms ( that ( have ( ( fewer ( valence electrons ) ) ( than ( they ( have ( valence orbitals ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Metallic) (NNS bonds)) (VP (VBP form) (PP (IN between) (NP (NP (NNS atoms)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (NP (NP (JJR fewer) (NN valence) (NNS electrons)) (SBAR (IN than) (S (NP (PRP they)) (VP (VBP have) (NP (JJ valence) (NNS orbitals)))))))))))) (. .)))
Metallic bonds form between atoms that have fewer valence electrons than they have valence orbitals.
(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)))) (. .)))