( ( ( An ( even number ) ) ( of ( ( protons or ) neutrons ) ) ) ( ( is ( ( ( more stable ) ( -LRB- ( ( lower ( binding energy ) ) -RRB- ) ) ) ( because ( ( of ( pairing effects ) ) ( , ( ( so ( even-even nuclides ) ) ( are ( ( much ( more stable ) ) ( than odd-odd ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT An) (JJ even) (NN number)) (PP (IN of) (NP (NNS protons) (CC or) (NNS neutrons)))) (VP (VBZ is) (ADJP (ADJP (RBR more) (JJ stable)) (PRN (-LRB- -LRB-) (S (VP (VB lower) (NP (JJ binding) (NN energy)))) (-RRB- -RRB-)) (SBAR (IN because) (S (PP (IN of) (NP (VBG pairing) (NNS effects))) (, ,) (NP (RB so) (JJ even-even) (NNS nuclides)) (VP (VBP are) (ADJP (ADJP (RB much) (RBR more) (JJ stable)) (PP (IN than) (ADJP (JJ odd-odd))))))))) (. .)))
An even number of protons or neutrons is more stable (lower binding energy) because of pairing effects, so even-even nuclides are much more stable than odd-odd.
(ROOT (S (NP (NP (NNP Nuclei)) (PP (IN with) (NP (NP (RB even) (NNS numbers)) (PP (IN of) (NP (NP (NNS protons)) (, ,) (NP (NNS neutrons)) (, ,) (CC or) (NP (DT both))))))) (VP (VBP are) (ADJP (RBR more) (JJ likely) (S (VP (TO to) (VP (VB be) (ADJP (JJ stable))))))) (. .)))