( ( A disintegration ) ( ( is ( ( the emission ) ( of ( an ( alpha ( , ( beta ( , ( or ( gamma particle ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN disintegration)) (VP (VBZ is) (NP (NP (DT the) (NN emission)) (PP (IN of) (NP (DT an) (NNP alpha) (, ,) (NN beta) (, ,) (CC or) (NN gamma) (NN particle))))) (. .)))
A disintegration is the emission of an alpha, beta, or gamma particle.
(ROOT (S (PP (IN Of) (NP (NP (DT the) (CD three) (JJ basic) (NNS types)) (PP (IN of) (NP (JJ radioactive) (NNS emissions))))) (, ,) (NP (DT the) (NN gamma) (NN particle)) (VP (VBZ is) (NP (DT the) (JJS most) (NN penetrating))) (. .)))