web analytics

Information Directory

Reference Directory

Specific Activities

The term “specific activity” is defined as the amount of radioactivity – or the decay rate – of a particular radionuclide per unit mass of the radionuclide. For example, the specific activity of Ra-226 is 1, meaning that one gram of Ra-226 contains one (1) curie (assumed to be uniformly distributed throughout that mass). It also means that there are 37,000,000,000 Ra-226 atoms disintegrating every second in a gram of Ra-226. In general, the higher a radionuclide’s specific activity, the shorter its half-life (decay rate), and the more “radioactive” it is when compared to one with a lower specific activity.

The following is a listing of specific activities, in units of “curies per gram” for a variety of radionuclides. For this listing the elements are shown alphabetically.  The specific activities are written in scientific notation (i.e., 7.2E1 is equal to 7.2 x 10, or 72).

Actinium

  • Ac-227 – 7.2E1
  • Ac-228 – 2.2E6

Americium

  • Am-241 – 3.2E0
  • Am-243 – 1.9E-1

Antimony

  • Sb-122 – 3.9E5
  • Sb-124 – 1.8E4
  • Sb-125 – 1.4E3

Argon

  • Ar-37 (compressed or uncompressed) – 1.0E5
  • Ar-41 (uncompressed) = 4.3E7
  • Ar-41 (compressed) – 4.3E7

Arsenic

  • As-73 – 2.4E4
  • As-74 – 1.0E5
  • As-76 – 1.6E6

Astatine

  • At-211 – 2.1E6

Barium

  • Ba-131 – 8.7E4
  • Ba-133 – 4.0E2
  • Ba-140 – 7.3E4

Berkelium

  • Bk-249 – 1.8E3

Beryllium

  • Be-7 – 3.5E5

Bismuth

  • Bi-206 – 9.9E4
  • Bi-207 – 2.2E2
  • Bi-210 – 1.2E5
  • Bi-212 – 1.5E7

Bromine

  • Br-77 – 7.1E5
  • Br-82 – 1.1E6

Cadmium

  • Cd-109 – 2.6E3
  • Cd-115m – 2.6E4
  • Cd-115 – 5.1E5

Calcium

  • Ca-45 – 1.9E4
  • Ca-47 – 5.9E5

Californium

  • Cf-249 – 3.1E0
  • Cf-250 – 1.3E2
  • Cf-252 – 5.4E2

Carbon

  • C-11 – 8.4E8
  • C-14 – 4.6E0

Cerium

  • Ce-139 – 6.5E3
  • Ce-141 – 2.8E4
  • Ce-143 – 6.6E5
  • Ce-144 – 3.2E3

Cesium

  • Cs-129 – 7.6E5
  • Cs-131 – 1.0E5
  • Cs-134m – 7.4E6
  • Cs-134 – 1.2E3
  • Cs-135 – 8.8E-4
  • Cs-136 – 7.4E4
  • Cs-137 – 8.8E1

Chlorine

  • Cl-36 – 3.2E-2
  • Cl-38 – 1.3E8

Chromium

  • Cr-51 – 9.2E4

Cobalt

  • Co-56 – 3.0E4
  • Co-57 – 8.5E3
  • Co-58m – 5.9E6
  • Co-58 – 3.1E4
  • Co-60 – 1.1E3

Copper

  • Cu-64 – 3.8E6
  • Cu-67 – 7.9E5

Curium

  • Cm-242 – 3.3E3
  • Cm-243 – 4.2E0
  • Cm-244 – 8.2E1
  • Cm-245 – 1.0E-1
  • Cm-246 – 3.6E-1

Dysprosium

  • Dy-165 – 8.2E6
  • Dy-166 – 2.3E5

Erbium

  • Er-169 – 8.2E4
  • Er-171 – 2.4E6

Europium

  • Eu-152m – 2.2E6
  • Eu-152 – 1.9E2
  • Eu-154 – 1.5E2
  • Eu-155 – 1.4E3

Fluorine

  • F-18 – 9.3E7

Gadolinium

  • Gd-153 – 3.6E3
  • Gd-159 – 1.1E6

Gallium

  • Ga-67 – 6.0E5
  • Ga-68 – 4.0E7
  • Ga-72 – 3.1E6

Germanium

  • Ge-68 – 7.0E3
  • Ge-71 – 1.6E5

Gold

  • Au-193 – 9.3E5
  • Au-196 – 1.2E5
  • Au-198 – 2.5E5
  • Au-199 – 2.1E5

Hafnium

  • Hf-181 – 1.6E4

Holmium

  • Ho-166 – 6.9E5

Hydrogen

  • H-3 (uncompressed) – 9.7E3
  • H-3 (compressed) – 9.7E3
  • H-3 (activated luminous paint) – 9.7E3
  • H-3 (adsorbed on solid carrier) – 9.7E3
  • H-3 (tritiated water) – 9.7E3
  • H-3 (other forms) – 9.7E3

Iodine

  • I-123 – 1.9E6
  • I-125 – 1.7E4
  • I-126 – 7.8E4
  • I-129 – 1.6E-4
  • I-131 – 1.2E5
  • I-132 – 1.1E7
  • I-133 – 1.1E6
  • I-134 – 2.7E7
  • I-135 – 3.5E6

Indium

  • In-111 – 4.2E5
  • In-113m – 1.6E7
  • In-114m – 2.3E4
  • In-115m – 6.1E6

Iridium

  • Ir-190 – 6.2E4
  • Ir-192 – 9.1E3
  • Ir-194 – 8.5E5

Iron

  • Fe-52 – 7.3E6
  • Fe-55 – 2.2E3
  • Fe-59 – 4.9E4

Krypton

  • Kr-85m(uncompressed) – 8.4E6
  • Kr-85m (compressed) – 8.4E6
  • Kr-85(uncompressed) – 4.0E2
  • Kr-85(compressed) – 4.0E2
  • Kr-87(uncompressed) – 2.8E7
  • Kr-87(compressed) – 2.8E7

Lanthanum

  • La-140 – 5.6E5

Lead

  • Pb-201 – 1.7E6
  • Pb-210 – 8.8E1
  • Pb-212 – 1.4E6

Lutetium

  • Lu-177 – 1.1E5

Magnesium

  • Mg-28 – 5.2E6

Manganese

  • Mn-52 – 4.4E5
  • Mn-54 – 8.3E3
  • Mn-56 – 2.2E7

Mercury

  • Hg-197m – 6.6E5
  • Hg-197 – 2.5E5
  • Hg-203 – 1.4E4

Molybdenum

  • Mo-99 – 4.7E5

Neodymium

  • Nd-147 – 8.0E4
  • Nd-149 – 1.1E7

Neptunium

  • Np-237 – 6.9E-4
  • Np-239 – 2.3E5

Nickel

  • Ni-59 – 8.1E-2
  • Ni-63 – 4.6E1
  • Ni-65 – 1.9E7

Niobium

  • Nb-93m – 1.1E3
  • Nb-95 – 3.9E4
  • Nb-97 – 2.6E7

Nitrogen

  • N-13 – 1.5E9

Osmium

  • Os-185 – 7.3E3
  • Os-191 – 4.6E4
  • Os-191m – 1.2E6
  • Os-193 – 5.3E5

Palladium

  • Pd-103 – 7.5E4
  • Pd-109 – 2.1E6

Phosphorus

  • P-32 – 2.9E5

Platinum

  • Pt-191 – 2.3E5
  • Pt-193m – 2.0E5
  • Pt-197m – 1.2E7
  • Pt-197 – 8.8E5

Potassium

  • K-40 – 7.04E-6
  • K-40 – 8.54E-10 per gram of natural K

Plutonium

  • Pu-238 – 1.7E1
  • Pu-239 – 6.2E-2
  • Pu-240 – 2.3E-1
  • Pu-241 – 1.1E2
  • Pu-242 – 3.9E-3

Polonium

  • Po-210 – 4.5E3

Potassium

  • K-42 – 6.0E6
  • K-43 – 3.3E6

Praseodymium

  • Pr-142 – 1.2E4
  • Pr-143 – 6.6E4

Promethium

  • Pm-147 – 9.4E2
  • Pm-149 – 4.2E5

Protactinium

  • Pa-230 – 3.2E4
  • Pa-231 – 4.5E-2
  • Pa-233 – 2.1E4

Radium

  • Ra-223 – 5.0E4
  • Ra-224 – 1.6E5
  • Ra-226 – 1.0E0
  • Ra-228 – 2.3E2

Radon

  • Rn-222 – 1.5E5

Rhenium

  • Re-186 – 1.9E5
  • Re-187 – 3.8E-8
  • Re-188 – 1.0E6
  • Re (natural) – 2.4E-8

Rhodium

  • Rh-103m – 3.2E7
  • Rh-105 – 8.2E5

Rubidium

  • Rb-81 – 8.2E6
  • Rb-86 – 8.1E4
  • Rb-87 – 6.6E-8
  • Rb (natural) – 1.8E-8

Ruthenium

  • Ru-97 – 5.5E5
  • Ru-103 – 3.2E4
  • Ru-105 – 6.6E6
  • Ru-106 – 3.4E3

Samarium

  • Sm-147 – 2.0E-8
  • Sm-151 – 2.6E1
  • Sm-153 – 4.4E5

Scandium

  • Sc-46 – 3.4E4
  • Sc-47 – 8.2E5
  • Sc-48 – 1.5E6

Selenium

  • Se-75 – 1.4E4

Silicon

  • Si-31 – 3.9E7

Silver

  • Ag-105 – 3.1E4
  • Ag-110m – 4.7E3
  • Ag-111 – 1.6E5

Sodium

  • Na-22 – 6.3E3
  • Na-24 – 8.7E6

Strontium

  • Sr-85m – 3.2E7
  • Sr-85 – 2.4E4
  • Sr-87m – 1.2E7
  • Sr-89 – 2.9E4
  • Sr-90 – 1.5E2
  • Sr-91 – 3.6E6
  • Sr-92 – 1.3E7

Sulphur

  • S-35 – 4.3E4

Tantalum

  • Ta-182 – 6.2E3

Technetium

  • Tc-96m – 3.8E7
  • Tc-96 – 3.2E5
  • Tc-97m – 1.5E4
  • Tc-97 – 1.4E-3
  • Tc-99m – 5.2E6
  • Tc-99 – 1.7E-2

Tellurium

  • Te-125m – 1.8E4
  • Te-127m – 4.0E4
  • Te-127 – 2.6E6
  • Te-129m – 2.5E4
  • Te-129 – 2.0E7
  • Te-131m – 8.0E5
  • Te-132 – 3.1E5

Terbium

  • Tb-160 – 1.1E4

Thallium

  • Tl-200 – 5.8E5
  • Tl-201 – 2.2E5
  • Tl-202 – 5.4E4
  • Tl-204 – 4.3E2

Thorium

  • Th-227 – 3.2E4
  • Th-228 – 8.3E2
  • Th-230 – 1.9E-2
  • Th-231 – 5.3E5
  • Th-232 – 1.1E-7
  • Th-234 – 2.3E4
  • Th (natural) – 2.2E-7

Thulium

  • Tm-270 – 6.0E3
  • Tm-171 – 1.1E3

Tin

  • Sn-113 – 1.0E4
  • Sn-119m – 4.4E3
  • Sn-125 – 1.1E5

Tungsten

  • W-181 – 5.0E3
  • W-185 – 9.7E-3
  • W-187 – 7.0E5

Uranium

  • U-230 – 2.7E4
  • U-232 – 2.1E1
  • U-233 – 9.5E-3
  • U-234 – 6.2E-3
  • U-235 – 2.1E-6
  • U-236 – 6.3E-5
  • U-238 – 3.3E-7
  • U (natural) – 7.1E-7 (0.72% U-235 present, by weight)
  • U (depleted) – 5.0E-7 – (0.45% U-235 present, by weight)
  • U (enriched) – 7.6E-7 (1% U-235 present, by weight)
  • U (enriched) – 1.0E-6 (1.5% U-235 present, by weight)
  • U (enriched) – 2.7E-6 (5% U-235 present, by weight)
  • U (enriched) – 4.8E-6 (10% U-235 present, by weight)
  • U (enriched) – 1.0E-5 (20% U-235 present, by weight)
  • U (enriched) – 2.0E-5 (35% U-235 present, by weight)
  • U (enriched) – 2.5E-5 (50% U-235 present, by weight)
  • U (enriched) – 5.8E-5 (90% U-235 present, by weight)
  • U (enriched) – 7.0E-5 (93% U-235 present, by weight)
  • U (enriched) – 9.1E-5 (95% U-235 present, by weight)

Vanadium

  • V-48 – 1.7E5

Xenon

  • Xe-127 (uncompressed) – 2.8E4
  • Xe-127 (compressed) – 2.8E4
  • Xe-131m (compressed) – 1.0E5
  • Xe-131m (uncompressed) – 1.0E5
  • Xe-133 (uncompressed) – 1.9E5
  • Xe-133 (compressed) – 1.9E5
  • Xe-135 (uncompressed) – 2.5E5
  • Xe-135 (compressed) – 2.5E5

Ytterbium

  • Yb-169 – 2.3E5
  • Yb-175 – 1.8E5

Yttrium

  • Y-87 – 4.5E1
  • Y-90 – 2.5E5
  • Y-91m – 4.1E7
  • Y-91 – 2.5E4
  • Y-92 – 9.5E6
  • Y-93 – 3.2E6

Zinc

  • Zn-65 – 8.0E3
  • Zn-69m – 3.3E6
  • Zn-69 – 5.3E7

Zirconium

  • Zr-93 – 3.5E-3
  • Zr-95 – 2.1E4
  • Zr-97 – 2.0E6