( ( ( The number ) ( of ( scintillations emitted ) ) ) ( ( is ( proportional ( to ( ( the energy ) ( of ( the ( beta particle ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NP (NNS scintillations)) (VP (VBN emitted))))) (VP (VBZ is) (ADJP (JJ proportional) (PP (TO to) (NP (NP (DT the) (NN energy)) (PP (IN of) (NP (DT the) (JJ beta) (NN particle))))))) (. .)))
The number of scintillations emitted is proportional to the energy of the beta particle.
(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))))))) (. .)))