词条 | Beryllium-8 |
释义 |
| background = #EEE | text_color = | isotope_name = Beryllium-8 | image = 鈹-8.svg | alternate_names = | mass_number = 8 | symbol = Be | num_neutrons = 4 | num_protons = 4 | abundance = Trace | halflife = 6.7(17)×10−17 s | error_halflife = | decay_product = | decay_mass =4 | decay_symbol =He | mass = 8.00530510(4) | spin =0 | excess_energy = | error1 = | binding_energy = | error2 = | decay_mode1 =α | decay_energy1 =6.8(17)×10−6 | decay_mode2 = | decay_energy2 = | decay_mode3 = | decay_energy3 = | decay_mode4 = | decay_energy4 = 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. FormationIn 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){{e|−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] TheoryGeorge Gamow, in his Big Bang theory, predicted that 8Be 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 higher elements to be created in stars. References1. ^{{Cite book|title=牛頓科學雜誌第42號 元素誕生的故事|last=|first=|publisher=牛頓媒體股份有限公司|accessdate=|year=|isbn=|location=|pages=30–37|language=Chinese}} {{Isotope|element=beryllium2. ^{{Cite book|title=牛頓科學雜誌第42號 元素誕生的故事|last=|first=|publisher=牛頓媒體股份有限公司|accessdate=|year=|isbn=|location=|pages=30–33|language=Chinese}} |lighter=Beryllium-7 |heavier=Beryllium-9 |before=Carbon-9 (β+, p) boron-9 (p, α) |after=helium-4 }} 2 : Beryllium|Isotopes of beryllium |
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