( ( ( The ( oxidation ( state ( and ( oxidation number ) ) ) ) ) ( of ( an ( ( atom or ) ion ) ) ) ) ( ( ( is simply ) ( defined ( as ( ( the sum ) ( of ( ( the ( ( ( negative and ) positive ) charges ) ) ( in ( an ( ( atom or ) ion ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN oxidation) (NN state) (CC and) (NN oxidation) (NN number)) (PP (IN of) (NP (DT an) (NN atom) (CC or) (NN ion)))) (VP (VBZ is) (ADVP (RB simply)) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN sum)) (PP (IN of) (NP (NP (DT the) (ADJP (JJ negative) (CC and) (JJ positive)) (NNS charges)) (PP (IN in) (NP (DT an) (NN atom) (CC or) (NN ion))))))))) (. .)))
The oxidation state and oxidation number of an atom or ion is  simply defined as the sum of the negative and positive charges in an atom or ion.
(ROOT (S (NP (DT An) (NN ion)) (VP (VBZ is) (NP (NP (DT an) (NN atom) (CC or) (NN group)) (PP (IN of) (NP (NP (VBN bonded) (NNS atoms)) (SBAR (WHNP (WDT that)) (S (VP (VBZ has) (NP (DT a) (ADJP (JJ positive) (CC or) (JJ negative)) (NN charge))))))))) (. .)))