( ( ( Beta decay ) ( -LRB- ( ( beta ( negative decay ) ) -RRB- ) ) ) ( ( occurs ( when ( ( a ( beta ( -LRB- ( negative ( -RRB- particle ) ) ) ) ) ( is ( released ( from ( ( the nucleus ) ( -LRB- ( i.e. ( , ( electron -RRB- ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Beta) (NN decay)) (PRN (-LRB- -LRB-) (NP (JJ beta) (JJ negative) (NN decay)) (-RRB- -RRB-))) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (JJ beta) (-LRB- -LRB-) (NN negative) (-RRB- -RRB-) (NN particle)) (VP (VBZ is) (VP (VBN released) (PP (IN from) (NP (NP (DT the) (NN nucleus)) (PRN (-LRB- -LRB-) (FW i.e.) (, ,) (ADJP (JJ electron)) (-RRB- -RRB-))))))))) (. .)))
Beta decay (beta negative decay) occurs when a beta (negative) particle is released from the nucleus ( i.e. , electron).
(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))))))) (. .)))