( ( Beta particles ) ( ( are ( emitted ( from ( ( the nucleus ) ( of ( certain ( radioactive atoms ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN Beta) (NNS particles)) (VP (VBP are) (VP (VBN emitted) (PP (IN from) (NP (NP (DT the) (NN nucleus)) (PP (IN of) (NP (JJ certain) (NN radioactive) (NNS atoms))))))) (. .)))
Beta particles are emitted from the nucleus of certain radioactive atoms.
(ROOT (S (NP (NN Beta) (NN decay)) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (DT an) (JJ unstable) (NN nucleus)) (VP (VBZ emits) (NP (NP (DT a) (JJ beta) (NN particle)) (CC and) (NP (NN energy))))))) (. .)))