( ( ( electron ( A ( subatomic particle ) ) ) ( with ( a ( negative charge ) ) ) ) . )
(ROOT (S (VP (VB electron) (NP (DT A) (JJ subatomic) (NN particle)) (PP (IN with) (NP (DT a) (JJ negative) (NN charge)))) (. .)))
electron  A subatomic particle with a negative charge.
(ROOT (S (NP (DT A) (NN redox) (NN reaction)) (VP (VBZ rearranges) (NP (NP (DT the) (JJ subatomic) (NNS particles)) (VP (VBN known) (PP (IN as) (NP (NNS electrons)))))) (. .)))