NAME

HALF-LIFE

Hydrogen-3 (tritium)

12 years

Beryllium-10

1 million 600 thousand years

Carbon-14

5 thousand 700 years

Silicon-32

500 years

Phosphorus-32

14 days

Potassium-40

1 thousand million years

Calcium-42

14 thousand years

Iron-55

3 years

Cobalt-60

5 years

Nickel-59

75 thousand years

Nickel-63

10 years

Selenium-79

65 thousand years

Krypton-81

200 thousand years

Krypton-83

10 years

Rubidium-87

47 thousand million years

Strontium-90

29 years

Yttrium-90

2 days

Zirconium-93

1 million 500 thousand years

Niobium-93m

14 years

Niobium-94

20 thousand years

Molybdenum-93

3 thousand 500 years

Technetium-99

200 thousand years

Ruthenium-106

1 year

Palladium-107

6 million 500 thousand years

Cadmium-113m

14 years

Tin-126

100 thousand years

Antimony-125

3 years

Antimony-126

12 days

Tellurium-125m

58 days

Iodine-129

15 million 700 thousand years

Cesium-134

2 years

Cesium-135

2 million 300 thousand years

Cesium-137

30 years

Cerium-144

3 hundred days

Promethium-147

3 years

Europium-154

9 years

Europium-155

5 years

Hafnium-182

9 million years

Tantalum-182

1 hundred days

Rhenium-187

50 thousand million years

Lead-205

14 million 300 thousand years

Lead-210

22 years

Bismuth-208

400 thousand years

Bismuth-210

5 days

Bismuth-210m

3 million years

Polonium-210

138 days

Radon-222

4 days

Radon-223

11 days

Radium-224

37 days

Radium-225

14 days

Radium-226

1 thousand 600 years

Radium-228

6 years

Actinium-225

10 days

Actinium-227

22 years

Thorium-227

19 days

Thorium-228

2 years

Thorium-229

7 thousand 300 years

Thorium-230

77 thousand years

Thorium-231

1 day

Thorium-232

14 thousand million years

Thorium-234

24 days

Protactinium-231

32 thousand 800 years

Protactinium-233

27 days

Protactinium-234

27 days

Uranium-232

72 years

Uranium-233

200 thousand years

Uranium-234

200 thousand years

Uranium-235

700 million years

Uranium-236

23 million years

Uranium-238

4 thousand million years

Neptunium-237

2 million years

Plutonium-238

88 years

Plutonium-239

24 thousand 100 years

Plutonium-240

6 thousand 500 years

Plutonium-241

14 years

Plutonium-242

400 thousand years

Americium-241

400 years

Americium-242m

100 years

Curium-244

18 years