鋇（原子量：137327 7）在自然界中有 7 種同位素，其中 6 個同位素穩定，剩下的 130Ba 則有微弱的放射性。除了 130Ba 以外，鋇還有 33 種人造放射性同位素。 圖表 rowspan4114Ba rowspan4 styletextalignright 56 rowspan4 styletextalignright 58 rowspan411395068 15 rowspan4530 230 ms 043 3015 s 9959 113Xe rowspan40 rowspan4 rowspan4 37 110Xe 04 114Cs 0034 Cluster decay is predicted but had never been observed 102Sn rowspan2115Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 59 rowspan211494737 64 rowspan2045 5 s 115Cs rowspan252 rowspan2 rowspan2 114Xe rowspan2116Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 60 rowspan211594138 43 rowspan213 2 s 116Cs rowspan20 rowspan2 rowspan2 115Xe rowspan3117Ba rowspan3 styletextalignright 56 rowspan3 styletextalignright 61 rowspan311693850 32 rowspan3175 7 s 117Cs rowspan332 rowspan3 rowspan3 α 113I 116Xe rowspan2118Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 62 rowspan211793304 21 rowspan252 2 s 118Cs rowspan20 rowspan2 rowspan2 117Xe rowspan2119Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 63 rowspan211893066 21 rowspan254 3 s 119Cs rowspan252 rowspan2 rowspan2 118Xe 120Ba styletextalignright 56 styletextalignright 64 11992604 32 24 2 s 120Cs 0 rowspan2121Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 65 rowspan212092405 15 rowspan2297 15 s 9998 121Cs rowspan252 rowspan2 rowspan2 02 120Xe 122Ba styletextalignright 56 styletextalignright 66 12191990 3 195 15 min 122Cs 0 123Ba styletextalignright 56 styletextalignright 67 122918781 13 27 4 min 123Cs 52 124Ba styletextalignright 56 styletextalignright 68 123915094 13 110 5 min 124Cs 0 125Ba styletextalignright 56 styletextalignright 69 124914473 12 35 4 min 125Cs 12 126Ba styletextalignright 56 styletextalignright 70 125911250 13 100 2 min 126Cs 0 127Ba styletextalignright 56 styletextalignright 71 126911094 12 127 4 min 127Cs 12 styletextindent1em 127mBa colspan3 styletextindent2em 8033 12 keV 19 2 s IT 127Ba 72 128Ba styletextalignright 56 styletextalignright 72 127908318 11 243 5 d 128Cs 0 129Ba styletextalignright 56 styletextalignright 73 128908679 12 223 11 h 129Cs 12 rowspan2 styletextindent1em 129mBa rowspan2 colspan3 styletextindent2em 842 6 keV rowspan2216 2 h 129Cs rowspan272 rowspan2 rowspan2 IT 129Ba 130BaPrimordial radioisotope styletextalignright 56 styletextalignright 74 1299063208 30 16 111021 yrs 130Xe 0 000106 1 styletextindent1em 130mBa colspan3 styletextindent2em 247512 18 keV 954 14 ms IT 130Ba 8 131Ba styletextalignright 56 styletextalignright 75 130906941 3 1150 6 d 131Cs 12 styletextindent1em 131mBa colspan3 styletextindent2em 18714 12 keV 146 2 min IT 131Ba 92 132Ba styletextalignright 56 styletextalignright 76 1319050613 11 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 132Xe with a halflife over 3001018 years 0 000101 1 133Ba styletextalignright 56 styletextalignright 77 1329060075 11 1051 5 yrs 133Cs 12 rowspan2 styletextindent1em 133mBa rowspan2 colspan3 styletextindent2em 288247 9 keV rowspan2389 1 h IT 9999 133Ba rowspan2112 rowspan2 rowspan2 0096 133Cs 134Ba styletextalignright 56 styletextalignright 78 1339045084 4 colspan3 aligncenter 0 002417 18 135Ba styletextalignright 56 styletextalignright 79 1349056886 4 colspan3 aligncenter 32 006592 12 styletextindent1em 135mBa colspan3 styletextindent2em 26822 2 keV 287 2 h IT 135Ba 112 136Ba styletextalignright 56 styletextalignright 80 1359045759 4 colspan3 aligncenter 0 007854 24 styletextindent1em 136mBa colspan3 styletextindent2em 2030466 18 keV 3084 19 ms IT 136Ba 7 137Ba styletextalignright 56 styletextalignright 81 1369058274 5 colspan3 aligncenter 32 011232 24 styletextindent1em 137m1Ba colspan3 styletextindent2em 661659 3 keV 2552 1 min IT 137Ba 112 styletextindent1em 137m2Ba colspan3 styletextindent2em 23491 4 keV 059 10 µs 172 138Ba 裂變產物 styletextalignright 56 styletextalignright 82 1379052472 5 colspan3 aligncenter 0 071698 42 styletextindent1em 138mBa colspan3 styletextindent2em 209054 6 keV 800 100 ns 6 139Ba styletextalignright 56 styletextalignright 83 1389088413 5 8306 28 min 139La 72 140Ba styletextalignright 56 styletextalignright 84 139910605 9 12752 3 d 140La 0 141Ba styletextalignright 56 styletextalignright 85 140914411 9 1827 7 min 141La 32 142Ba styletextalignright 56 styletextalignright 86 141916453 7 106 2 min 142La 0 143Ba styletextalignright 56 styletextalignright 87 142920627 14 145 3 s 143La 52 144Ba styletextalignright 56 styletextalignright 88 143922953 14 115 2 s 144La 0 145Ba styletextalignright 56 styletextalignright 89 14492763 8 431 16 s 145La 52 rowspan2146Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 90 rowspan214593022 8 rowspan2222 7 s 9998 146La rowspan20 rowspan2 rowspan2 02 145La rowspan2147Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 91 rowspan214693495 22 rowspan20893 1 s 9994 147La rowspan232 rowspan2 rowspan2 06 146La rowspan2148Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 92 rowspan214793772 9 rowspan20612 17 s 996 148La rowspan20 rowspan2 rowspan2 4 147La rowspan2149Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 93 rowspan214894258 21 rowspan2344 7 ms 9957 149La rowspan232 rowspan2 rowspan2 43 148La rowspan2150Ba rowspan2 styletextalignright 56 rowspan2 styletextalignright 94 rowspan214994568 43 rowspan2300 ms 150La rowspan20 rowspan2 rowspan2 （不常見） 149La 151Ba styletextalignright 56 styletextalignright 95 15095081 43 200 ms 300 ns 151La 32 152Ba styletextalignright 56 styletextalignright 96 15195427 54 100 ms 152La 0 153Ba styletextalignright 56 styletextalignright 97 15295961 86 80 ms 153La 52 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 Ba Category 鋇