Nuclear Elements
Radioactive and nuclear-relevant elements - from hydrogen to californium. How they behave, their applications, and their dangers.
1
H
1.008
Hydrogen
nonmetal ยท gas
The lightest and most abundant element in the universe. Fuel for fusion reactors and the Sun.
2
He
4.003
Helium
noble-gas ยท gas
Noble gas produced by alpha decay of heavy elements. Used in MRI machines and balloons.
6
C
12.011
Carbon
nonmetal ยท solid
Carbon-14 is a radioactive isotope used in radiocarbon dating of organic materials.
27
Co
58.933
Cobalt
transition ยท solid
Cobalt-60 is a radioactive isotope used in cancer radiotherapy and food irradiation.
36
Kr
83.798
Krypton
noble-gas ยท gas
Krypton-85 is a fission product released in nuclear reactor operations and accidents.
38
Sr
87.62
Strontium
alkaline ยท solid
Strontium-90 is a radioactive fission product that mimics calcium, concentrating in bones.
43
Tc
97
Technetium
โข Radioactive
transition ยท solid
The lightest element with no stable isotopes. Tc-99m is the most widely used medical imaging isotope.
53
I
126.904
Iodine
halogen ยท solid
Iodine-131, a fission product, caused most thyroid cancers after Chernobyl. Potassium iodide pills protect the thyroid.
54
Xe
131.293
Xenon
noble-gas ยท gas
Xenon-135 is a powerful neutron absorber ("reactor poison") produced during fission that can cause shutdown.
55
Cs
132.905
Caesium
alkali ยท solid
Caesium-137 is one of the most dangerous fission products. Its 30-year half-life made it the main Chernobyl contaminant.
79
Au
196.967
Gold
transition ยท solid
Gold-198 is used in some cancer treatments and as a radioactive tracer in medical diagnostics.
82
Pb
207.2
Lead
post-trans ยท solid
Lead is the stable endpoint of uranium, thorium and radium decay chains. Used as radiation shielding.
83
Bi
208.98
Bismuth
post-trans ยท solid
Bismuth-213 is used in targeted alpha therapy for cancer. Bismuth-209 is the heaviest stable (quasi-stable) isotope.
84
Po
209
Polonium
โข Radioactive
post-trans ยท solid
Highly radioactive. Polonium-210 was used to assassinate Alexander Litvinenko in 2006 in London.
86
Rn
222
Radon
โข Radioactive
noble-gas ยท gas
A colourless radioactive gas produced by uranium decay. The second-leading cause of lung cancer after smoking.
88
Ra
226
Radium
โข Radioactive
alkaline ยท solid
Discovered by Marie Curie in 1898. Once used in luminous watch dials. Its decay produces radon gas.
90
Th
232.038
Thorium
โข Radioactive
actinide ยท solid
Thorium-232 is a fertile material that can breed fissile U-233. Some reactors use thorium as fuel instead of uranium.
91
Pa
231.036
Protactinium
โข Radioactive
actinide ยท solid
A rare, highly toxic actinide produced by thorium decay. Little practical application due to scarcity.
92
U
238.029
Uranium
โข Radioactive
actinide ยท solid
The primary fuel for nuclear reactors. U-235 is fissile (splits easily); U-238 is fertile (can breed Pu-239).
93
Np
237
Neptunium
โข Radioactive
actinide ยท solid
The first synthetic transuranium element, produced in reactors as a byproduct of U-238 neutron capture.
94
Pu
244
Plutonium
โข Radioactive
actinide ยท solid
Produced in reactors from U-238. Pu-239 is used in nuclear weapons and as reactor fuel (MOX). Highly toxic.
95
Am
243
Americium
โข Radioactive
actinide ยท solid
Used in smoke detectors (Am-241). Produced in reactors from plutonium. Part of nuclear waste.
96
Cm
247
Curium
โข Radioactive
actinide ยท solid
Named after Marie and Pierre Curie. Highly radioactive. Used as a power source in space probes.
98
Cf
251
Californium
โข Radioactive
actinide ยท solid
Californium-252 is a potent neutron source used to start nuclear reactors and in cancer treatment.
99
Es
252
Einsteinium
โข Radioactive
actinide ยท solid
Discovered in 1952 in debris from the first hydrogen bomb test. Named after Albert Einstein.