( This ( ( maximizes ( ( the ( attractive forces ) ) ( between ( ( ( positive and ) negative ) ions ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ maximizes) (NP (NP (DT the) (JJ attractive) (NNS forces)) (PP (IN between) (NP (ADJP (JJ positive) (CC and) (JJ negative)) (NNS ions))))) (. .)))
This maximizes the attractive forces between positive and negative ions.
(ROOT (S (NP (JJ Electrical) (NN force)) (VP (VBZ has) (NP (JJ negative) (NN attraction))) (. .)))
Electrical force has negative attraction.