( ( An ( ionic compound ) ) ( ( consists ( of ( ( the combination ) ( of ( metal ( and ( nonmetal elements ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT An) (JJ ionic) (NN compound)) (VP (VBZ consists) (PP (IN of) (NP (NP (DT the) (NN combination)) (PP (IN of) (NP (NN metal) (CC and) (NN nonmetal) (NNS elements)))))) (. .)))
An ionic compound consists of the combination of metal and nonmetal elements.
(ROOT (S (NP (NP (JJ Ionic) (NNS bonds)) (PP (IN between) (NP (CD two) (NNS atoms)))) (VP (VBP require) (NP (NP (CD one) (NN metal)) (CC and) (NP (CD one) (NN nonmetal)))) (. .)))