This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10−19 and 10−10 seconds.Reaching the limits of nuclear stability, M. Thoennessen, Rep. Prog. Phys. 67 (2004), pp. 1187–1232, §2.3, .
10−24 seconds (yoctoseconds) isotopehalf-life10−24 secondshydrogen-586lithium-491hydrogen-4139nitrogen-10143oxygen-11198helium-10260hydrogen-6294lithium-5370fluorine-14500boron-7570nitrogen-11585helium-5602beryllium-16650oxygen-28≥650hydrogen-7652nitrogen-11m690boron-21>760neon-15770beryllium-15790boron-20>912.4fluorine-30960 Twenty-three yoctoseconds is the time needed to traverse a 7-femtometre distance at the speed of light—around the diameter of a large atomic nucleus.
10−21 seconds (zeptoseconds) isotopehalf-life10−21 secondsberyllium-131.0aluminium-20>1.1aluminium-21>1.1fluorine-151.1sodium-181.34lithium-102.0oxygen-27≥2.5helium-92.5helium-72.51lithium-133.3carbon-83.5magnesium-184.0boron-16>4.6beryllium-65.0oxygen-255.18chlorine-295.4neon-16>5.7oxygen-128.9fluorine-1621fluorine-2846boron-9800
10−18 seconds (attoseconds) isotopehalf-life10−18 secondsnitrogen-9<1sodium-19>1beryllium-881.9
10−12 seconds (picoseconds) isotopehalf-life10−12 secondsoxygen-264.2magnesium-195argon-30<10potassium-31<10sodium-22m219.6
10−9 seconds (nanoseconds) isotopehalf-life10−9 secondshelium-2<1tellurium-1047.2This appears reliable but the NUBASE2020 value is <4 ns and the discrepancy is yet to be explained.lithium-12<10boron-18<26chlorine-30<50protactinium-21953sodium-3760protactinium-220m269actinium-21769francium-21586lead-196m1<100uranium-236m1100bismuth-199m2100curium-247m2100.6actinium-218m103francium-214m2103bismuth-201m3105lead-202m3107francium-214m3108thorium-218109lead-202m2110neptunium-238m112phosphorus-26m115polonium-205m4115bismuth-201m2118uranium-236m2120lead-203m3122bismuth-201m4124astatine-213125lead-193m2135lead-198m2137lead-196m3140lead-190m1150thallium-198m2150fluorine-18m162americium-239m163lead-192m1164bismuth-199m3168magnesium-40>170aluminium-42>170aluminium-43>170sodium-36180curium-242m180radium-216182plutonium-239m1193bismuth-203m2194aluminium-32m200polonium-198m1200phosphorus-46>200sulfur-47>200sulfur-48>200chlorine-48>200chlorine-49>200chlorine-51>200argon-51>200polonium-202m>200neodymium-126>200polonium-203m2>200lead-210m201lead-206m2202bismuth-197m2204polonium-207m1205bismuth-197m5209silicon-34m<210lead-198m3212lead-205m3217polonium-206m1222beryllium-12m233thallium-205m2235polonium-211m2243sodium-22m1243radon-214m245uranium-239m1>250bismuth-197m4253fluorine-31>260polonium-210m263bismuth-197m3263lead-204m1265astatine-214m1265radium-208m270lead-196m4270radon-214270uranium-238m280curium-245m290thallium-192m2296polonium-212299protactinium-220m1308bismuth-202m2310polonium-205m1310plutonium-243m330thallium-200m2330silicon-44>360neptunium-222380lead-216m400sodium-39>400phosphorus-47>400sulfur-49>400chlorine-52>400argon-54>400astatine-206m410sulfur-43m415protactinium-229m420lead-204m3450lead-208m500bismuth-190m2>500curium-244m2>500lead-201m2508radium-215m3555astatine-214558berkelium-242m600thorium-216m2615chlorine-50>620argon-52>620argon-53>620radon-210m1644uranium-221660francium-216700actinium-217m740bismuth-195m2750polonium-198m2750lead-192m3756astatine-214m2760protactinium-220780uranium-239m2780lead-188m2797lead-188m1830radium-212m2850polonium-196m850bismuth-189m2880plutonium-241m1880
10−6 seconds (microseconds) isotopehalf-life10−6 secondslead-196m2<1polonium-192m~1radon-210m31.04thorium-2191.05polonium-206m21.05radon-210m21.06curium-243m1.08actinium-2181.08lead-192m21.1plutonium-237m21.1lead-197m21.15americium-241m1.2radium-215m21.39bismuth-211m1.4uranium-2221.4neon-34>1.5radium-2171.63neptunium-2232.15radium-210m2.24radon-2152.30sulfur-44m2.619bismuth-217m2.70polonium-211m32.8radon-209m23.0bismuth-202m13.04polonium-2133.65lead-198m14.19sodium-26m4.35protactinium-2214.9nitrogen-16m5.25astatine-210m25.66nobelium-2505.7lead-212m6.0lead-214m6.2bismuth-187m27thorium-229m7radium-215m17.1lead-190m37.2plutonium-239m27.5bismuth-206m17.7astatine-205m7.76thorium-2209.7lead-195m210.0lead-199m210.1radium-212m110.9astatine-196m211actinium-21911.8radon-209m113.4polonium-194m15caesium-11316.7francium-21716.8uranium-22321plutonium-241m221fermium-251m21.1curium-249m23rutherfordium-25423sodium-32m24lead-205m124.2neptunium-22025lead-190m225radium-21825.2lead-189m226curium-247m126.3berkelium-250m129nobelium-253m31polonium-18634americium-238m35nobelium-250m36neptunium-22438californium-249m45radon-21645rutherfordium-25348bismuth-185m49polonium-207m249radium-231m~53uranium-21955berkelium-251m58americium-246m273seaborgium-261m92astatine-215100astatine-216m100protactinium-218113lead-206m1125thorium-216m1137curium-248m146neptunium-219150astatine-212m2152polonium-214164.3radon-207m181bismuth-207m182darmstadtium-270205berkelium-250m2213darmstadtium-269230lead-178230copernicium-277240thorium-217240darmstadtium-273240berkelium-249m300astatine-216300bismuth-187m1320nihonium-278340hassium-265m360fermium-258370polonium-188430actinium-216440actinium-216m443astatine-210m1482caesium-112500polonium-187m500hassium-264540radon-217540polonium-205m2645copernicium-277690oganesson-294690fermium-241730hassium-263760fermium-242800bismuth-206m2890mendelevium-245900copernicium-282910uranium-224940
10−3 seconds (milliseconds) isotopehalf-life10−3 secondsfrancium-2181.0bismuth-204m21.07protactinium-217m1.08meitnerium-2661.2nobelium-2581.2uranium-216m1.31polonium-1871.40nihonium-2781.4sodium-351.5radium-2151.55darmstadtium-271m1.7astatine-1911.7thorium-2081.7thorium-2211.73polonium-2151.781hassium-2651.96bismuth-1852roentgenium-2722astatine-191m2.1radium-213m2.1fluorine-26m2.2thorium-2222.237uranium-2152.24polonium-1902.46fluorine-292.5flerovium-2842.5bismuth-208m2.58radium-2022.6boron-192.92seaborgium-2583hassium-2663.02magnesium-383.1fermium-2443.12protactinium-2223.2francium-214m13.35neon-313.4protactinium-2173.48neon-323.5aluminium-413.5darmstadtium-2773.5protactinium-2113.8magnesium-363.9lead-1793.9silicon-45~4roentgenium-2784radium-2034seaborgium-2604uranium-2164.3lead-1804.5beryllium-144.53radon-1964.7fluorine-275bismuth-189m15.0francium-2145.0meitnerium-2775nobelium-2625polonium-1895boron-175.08protactinium-2235.1americium-2235.2sodium-345.5lead-205m25.55aluminium-405.7neptunium-2256uranium-2186radon-1956radon-195m6carbon-226.2meitnerium-2706.3rutherfordium-2566.4bismuth-1846.6thorium-2097protactinium-2137seaborgium-2627neon-307.22aluminium-397.6protactinium-2128sodium-338magnesium-378fluorine-268.2livermorium-2908.3oxygen-138.58lithium-118.75aluminium-389bohrium-262m9.6thorium-2079.7bismuth-186m9.8darmstadtium-270m10radium-21910boron-1510.18hassium-27711nitrogen-1211magnesium-3511.3aluminium-3711.4astatine-19211.5bohrium-26111.8roentgenium-27412boron-1412.36silicon-4313bismuth-204m113livermorium-29213bismuth-184m13sodium-3213.2nitrogen-2313.9americium-242m214.0protactinium-21514neon-2914.7rutherfordium-25814.7bismuth-18614.8argon-3115actinium-206m115silicon-4215.5carbon-2016francium-19916sulfur-2716.3protactinium-21417sodium-3117thorium-21017boron-1317.16radium-22017.9phosphorus-4418.5neon-2818.8livermorium-29119radon-21319.5silicon-4120actinium-20520astatine-196m120rutherfordium-27020francium-21920meitnerium-27520sodium-24m20.18boron-1220.2radon-197m21rutherfordium-26021astatine-193m121californium-23821.1beryllium-1221.46francium-218m122.0tennessine-29322polonium-19122aluminium-34m22.1nitrogen-2223phosphorus-4524francium-20024actinium-20625uranium-21726actinium-22026.36thorium-21626.8meitnerium-26827astatine-193m227lawrencium-25127actinium-208m28astatine-19328manganese-6828silicon-2228.7sodium-2830.5neon-2730.9actinium-20731silicon-4031.2bismuth-18732polonium-19232.2astatine-21732.3aluminium-3232.6uranium-234m33.5curium-244m134bohrium-26035radon-21835neptunium-22635phosphorus-4235.8thorium-21236moscovium-28737seaborgium-26437dubnium-25537aluminium-3538.16actinium-206m241radium-203m41silicon-3941.2aluminium-3341.46silicon-2342.3phosphorus-2643.6bismuth-18844sodium-2944.9magnesium-3444.9lead-18145carbon-1946.2thorium-21148sodium-3048.4phosphorus-4248.5fluorine-2550sulfur-4650tennessine-29451actinium-22152aluminium-3453.73hassium-26755radium-207m57livermorium-29357polonium-205m357.4radium-20460lead-18260uranium-22561silicon-3863radon-19865radon-19766francium-20167sulfur-4568nihonium-28273nihonium-28375oxygen-2477.4magnesium-3280.4bohrium-26284nitrogen-2185astatine-192m88aluminium-3690darmstadtium-27190roentgenium-27990magnesium-2090.4aluminium-2291.1carbon-1892magnesium-3392actinium-20992polonium-191m93oxygen-2397actinium-20897argon-3298copernicium-28498sulfur-44100thorium-214100flerovium-285100phosphorus-41101chlorine-47101protactinium-216105argon-50106nobelium-260106astatine-204m108neon-17109.2astatine-212m1119helium-8119.5magnesium-21120flerovium-286120seaborgium-263m120bismuth-191m124sulfur-28125carbon-9126.5aluminium-24m130nitrogen-20136thorium-213140silicon-37141silicon-24143.2polonium-216145astatine-195m147phosphorus-40150moscovium-288164actinium-215170argon-33173lithium-9178.2copernicium-281180radium-205m180plutonium-237m1180sulfur-29188chlorine-31190carbon-17193neon-26197mendelevium-247m200seaborgium-261200darmstadtium-279210actinium-211213bismuth-188m220radium-205220silicon-25220.6fermium-243231chlorine-46232argon-49236polonium-193m240radium-206240astatine-196253phosphorus-27260sulfur-43265uranium-226269magnesium-31270phosphorus-28270.3hassium-266m280nobelium-254m280phosphorus-39282astatine-194286hassium-275290francium-202290chlorine-32298sodium-27301bismuth-203m1303astatine-212314magnesium-30317radon-199m320astatine-194m323astatine-195328moscovium-289330nitrogen-19336francium-202m340actinium-210350seaborgium-266360fluorine-24384astatine-197388lawrencium-252390polonium-194392bismuth-200m2400mendelevium-245m400mendelevium-244400argon-48415lead-183m415polonium-193420meitnerium-274440aluminium-23446sodium-20447.9meitnerium-276450astatine-202m2460flerovium-287480lead-203m2480lead-184490silicon-36503hassium-273510neptunium-227510dubnium-259510chlorine-45513polonium-211516lead-183535francium-203550chlorine-44560lawrencium-253580thorium-223600bismuth-196m1600seaborgium-259600neon-25602nitrogen-18619.2radon-199620phosphorus-38640aluminium-31644lawrencium-257646moscovium-290650francium-200m650flerovium-288660dubnium-257m670bismuth-189674francium-206m2700chlorine-38m715actinium-213731carbon-16750boron-8771.9silicon-35780nobelium-251780lead-207m806helium-6806.92lithium-8838.7protactinium-224844argon-34846.46bohrium-265900bohrium-266900lutetium-153900nihonium-284910actinium-212920radon-200960bohrium-264970
100 seconds