Beryllium-8

Beryllium-8
General
Name, symbol Beryllium-8,8Be
Neutrons 4
Protons 4
Nuclide data
Natural abundance Trace
Half-life 6.7(17)×10−17 s
Decay products 4He
Isotope mass 8.00530510(4) u
Spin 0
Decay modes
Decay mode Decay energy (MeV)
α 6.8(17)×10−6
Complete table of nuclides

Beryllium-8 is an isotope of beryllium with 4 neutrons and 4 protons, and four electrons when its oxidation state is 0. It is one of the radionuclides.

Formation

In stellar nucleosynthesis, two helium-4 nuclei may collide and fuse into a single beryllium-8 nucleus. Beryllium-8 has an extremely short half-life (6.7(17)×10−17 seconds), and decays back into two helium-4 nuclei. If the beryllium-8 collides with a helium-4 nucleus before decaying, they can fuse into a carbon-12 nuclei. This is called the triple-alpha process, or "helium burning".[1]

Theory

George Gamow, in his Big Bang theory, predicted that Be-8 decays too fast to sustain nuclear fusion. This would mean that only Hydrogen, Helium and Lithium would be produced and not the elements which have a higher mass.[2] Fred Hoyle subsequently theorized the Triple-alpha process which would allow for higher elements to be created in stars.

Triple-alpha process

References

  1. ↑ 牛頓科學雜誌第42號 元素誕生的故事 (in 中文). 牛頓媒體股份有限公司. pp. 30–37.
  2. ↑ 牛頓科學雜誌第42號 元素誕生的故事 (in 中文). 牛頓媒體股份有限公司. pp. 30–33.
Lighter:
Beryllium-7		 Beryllium-8 is an
isotope of beryllium		 Heavier:
Beryllium-9
Decay product of:
Carbon-9 (β+, p)
boron-9 (p, α)		 Decay chain
of beryllium-8		 Decays to:
helium-4
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