( ( ( An understanding ) ( of ( ( the forces ) ( that ( ( ( hold molecules ) together ) ( in ( ( ( ( the ( solid state ) ) ( -LRB- ( i.e. ( , ( ( ( ( ionic ( , ( ( Van ( de Waals ) ) , ) ) ) and ) dipole ) -RRB- ) ) ) ) ) and ) ( those ( that ( ( allow ( the solid ) ) ( to ( have ( ( its molecules ) ( separated ( by ( solvent molecules ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ( ( is useful ) . ) )
(ROOT (S (NP (NP (DT An) (NN understanding)) (PP (IN of) (NP (NP (DT the) (NNS forces)) (SBAR (WHNP (WDT that)) (S (VP (VBP hold) (NP (NNS molecules)) (ADVP (RB together)) (PP (IN in) (NP (NP (NP (DT the) (JJ solid) (NN state)) (PRN (-LRB- -LRB-) (FW i.e.) (, ,) (ADJP (ADJP (ADJP (JJ ionic)) (PRN (, ,) (NP (NNP Van) (NNP de) (NNP Waals)) (, ,))) (CC and) (ADJP (JJ dipole))) (-RRB- -RRB-))) (CC and) (NP (NP (DT those)) (SBAR (WHNP (WDT that)) (S (VP (VBP allow) (NP (DT the) (JJ solid)) (S (VP (TO to) (VP (VB have) (NP (NP (PRP$ its) (NNS molecules)) (VP (VBN separated) (PP (IN by) (NP (JJ solvent) (NNS molecules)))))))))))))))))))) (VP (VBZ is) (ADJP (JJ useful))) (. .)))
An understanding of the forces that hold molecules together in the solid state (i.e., ionic, Van de Waals, and dipole) and those that allow the solid to have its molecules separated by solvent molecules is useful.
(ROOT (S (NP (NNP Solid)) (VP (VBZ is) (VP (VBN characterized) (PP (IN by) (NP (NP (NP (NNS molecules)) (PP (IN with) (NP (JJ minimal) (NN movement)))) (CC and) (NP (NP (JJ strong) (NNS forces)) (PP (IN between) (NP (PRP them)))))))) (. .)))