硒（原子量：7896 3）共有 39 個同位素，其中有 5 個同位素是穩定的。 圖表 rowspan265Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 31 rowspan26496466 64 rowspan250 ms 999 65As rowspan232 rowspan2 rowspan2 1 64Ge 66Se styletextalignright 34 styletextalignright 32 6595521 32 33 12 ms 66As 0 rowspan267Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 33 rowspan26695009 21 rowspan2133 11 ms 995 67As rowspan252 rowspan2 rowspan2 5 66Ge 68Se styletextalignright 34 styletextalignright 34 6794180 4 355 7 s 68As 0 rowspan269Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 35 rowspan26893956 4 rowspan2274 2 s 99955 69As rowspan212 rowspan2 rowspan2 045 68Ge styletextindent1em 69m1Se colspan3 styletextindent2em 394 1 keV 20 2 µs 52 styletextindent1em 69m2Se colspan3 styletextindent2em 5739 10 keV 955 16 ns 92 70Se styletextalignright 34 styletextalignright 36 6993339 7 411 3 min 70As 0 71Se styletextalignright 34 styletextalignright 37 7093224 3 474 5 min 71As 52 styletextindent1em 71m1Se colspan3 styletextindent2em 4879 5 keV 56 7 µs 12 to 92 styletextindent1em 71m2Se colspan3 styletextindent2em 26048 10 keV 190 5 µs 92 72Se styletextalignright 34 styletextalignright 38 71927112 13 840 8 d 72As 0 73Se styletextalignright 34 styletextalignright 39 72926765 11 715 8 h 73As 92 rowspan2 styletextindent1em 73mSe rowspan2 colspan3 styletextindent2em 2571 4 keV rowspan2398 13 min IT 73Se rowspan232 rowspan2 rowspan2 73As 74Se styletextalignright 34 styletextalignright 40 739224764 18 colspan3 aligncenter 觀測上穩定 Believed to decay by to 74Ge 0 00089 4 75Se styletextalignright 34 styletextalignright 41 749225234 18 119779 4 d 75As 52 76Se styletextalignright 34 styletextalignright 42 759192136 18 colspan3 aligncenter 0 00937 29 77Se styletextalignright 34 styletextalignright 43 769199140 18 colspan3 aligncenter 12 00763 16 styletextindent1em 77mSe colspan3 styletextindent2em 1619223 7 keV 1736 5 s IT 77Se 72 78Se styletextalignright 34 styletextalignright 44 779173091 18 colspan3 aligncenter 0 02377 28 Longlived fission product styletextalignright 34 styletextalignright 45 789184991 18 327 8105 y 79Br 72 rowspan2 styletextindent1em 79mSe rowspan2 colspan3 styletextindent2em 9577 3 keV rowspan2392 1 min IT 99944 79Se rowspan212 rowspan2 rowspan2 056 79Br styletextalignright 34 styletextalignright 46 799165213 21 colspan3 aligncenter 觀測上穩定 Believed to decay by to 80Kr 0 04961 41 81Se styletextalignright 34 styletextalignright 47 809179925 22 1845 12 min 81Br 12 rowspan2 styletextindent1em 81mSe rowspan2 colspan3 styletextindent2em 10299 6 keV rowspan25728 2 min IT 99948 81Se rowspan272 rowspan2 rowspan2 052 81Br 82SePrimordial radionuclide styletextalignright 34 styletextalignright 48 819166994 22 097 51020 y 82Kr 0 00873 22 83Se styletextalignright 34 styletextalignright 49 82919118 4 223 3 min 83Br 92 styletextindent1em 83mSe colspan3 styletextindent2em 22850 20 keV 701 4 s 83Br 12 84Se styletextalignright 34 styletextalignright 50 83918462 16 31 1 min 84Br 0 85Se styletextalignright 34 styletextalignright 51 8492225 3 317 9 s 85Br 52 86Se styletextalignright 34 styletextalignright 52 85924272 17 153 9 s 86Br 0 rowspan287Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 53 rowspan28692852 4 rowspan2550 12 s 9964 87Br rowspan252 rowspan2 rowspan2 36 86Br rowspan288Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 54 rowspan28793142 5 rowspan2153 6 s 9901 88Br rowspan20 rowspan2 rowspan2 99 88Br rowspan289Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 55 rowspan28893645 32 rowspan2041 4 s 922 89Br rowspan252 rowspan2 rowspan2 78 88Br rowspan290Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 56 rowspan28993996 43 rowspan2300 ms 300 ns 89Br rowspan20 rowspan2 rowspan2 90Br rowspan291Se rowspan2 styletextalignright 34 rowspan2 styletextalignright 57 rowspan29094596 54 rowspan2270 50 ms 79 91Br rowspan212 rowspan2 rowspan2 90Br 92Se styletextalignright 34 styletextalignright 58 9194992 64 100 ms 300 ns 92Br 0 93Se styletextalignright 34 styletextalignright 59 9295629 86 50 ms 300 ns 12 94Se styletextalignright 34 styletextalignright 60 9396049 86 20 ms 300 ns 0 參考文獻 Isotope masses from Ame2003 Atomic Mass Evaluation by G Audi AH Wapstra C Thibault J Blachot and O Bersillon in Nuclear Physics A729 2003 Isotopic compositions and standard atomic masses from Atomic weights of the elements Review 2000 IUPAC Technical Report Pure Appl Chem Vol 75 No 6 pp 683800 2003 and Atomic Weights Revised 2005 Halflife spin and isomer data selected from these sources Editing notes on this articles talk page Audi Bersillon Blachot Wapstra The Nubase2003 evaluation of nuclear and decay properties Nuc Phys A 729 pp 3128 2003 National Nuclear Data Center Brookhaven National Laboratory Information extracted from the NuDat 21 database retrieved Sept 2005 David R Lide ed Norman E Holden in CRC Handbook of Chemistry and Physics 85th Edition online version CRC Press Boca Raton Florida 2005 Section 11 Table of the Isotopes Se Category 硒