( ( ( Radioactivity : ) ( ( Spontaneous disintegration ) ( of ( ( the ( atomic nucleus ) ) ( of ( ( some ( chemical elements ) ) ( with ( ( the emission ) ( of ( ( ( ( energetic and ) charged ) particles ) ( -LRB- ( ( ( alpha , ) ( beta ( and ( gamma rays ) ) ) ) -RRB- ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NNP Radioactivity)) (: :) (NP (NP (NNP Spontaneous) (NNP disintegration)) (PP (IN of) (NP (NP (DT the) (JJ atomic) (NN nucleus)) (PP (IN of) (NP (NP (DT some) (JJ chemical) (NNS elements)) (PP (IN with) (NP (NP (DT the) (NN emission)) (PP (IN of) (NP (NP (ADJP (JJ energetic) (CC and) (VBN charged)) (NNS particles)) (PRN (-LRB- -LRB-) (NP (NP (NNP alpha)) (, ,) (NP (NN beta) (CC and) (NN gamma) (NNS rays))) (-RRB- -RRB-))))))))))) (. .)))
Radioactivity: Spontaneous disintegration of the atomic nucleus of some chemical elements with the emission of energetic and charged particles (alpha, beta and gamma rays).
(ROOT (S (NP (NNP Alpha) (NNP emission)) (VP (VBZ is) (NP (NP (DT a) (NN type)) (PP (IN of) (NP (NN radioactivity))))) (. .)))