Beryllium-8,  8Be
Name, symbolBeryllium-8,8Be
Nuclide data
Natural abundance0[a]
Half-life8.19(37)×10−17 s
Decay products4He
Isotope mass8.00530510(4) u
Decay modes
Decay modeDecay energy (MeV)
Isotopes of beryllium
Complete table of nuclides

Beryllium-8 (8Be) is an unstable radionuclide with 4 neutrons and 4 protons. It is an unbound resonance and nominally an isotope of beryllium. It decays into two alpha particles with a half-life on the order of 10−16 seconds; this has important ramifications in stellar nucleosynthesis as it creates a bottleneck in the creation of heavier chemical elements. The properties of 8Be have also led to speculation on the fine tuning of the Universe, and theoretical investigations on cosmological evolution had 8Be been stable.


The discovery of beryllium-8 occurred shortly after the construction of the first particle accelerator in 1932. British physicists John Douglas Cockcroft and Ernest Walton performed their first experiment with their accelerator at the Cavendish Laboratory in Cambridge, in which they irradiated lithium-7 with protons. They reported that this populated a nucleus with A = 8 that near-instantaneously decays into two alpha particles. This activity was observed again several months later, and was inferred to originate from 8Be.[3]

Other Languages
interlingua: Beryllium-8
italiano: Berillio-8
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日本語: ベリリウム8
中文: 鈹-8