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Beryllium-8 (8 Be, Be-8) is a 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 8.19 × 10 −17 seconds.
Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons. There are 25 other monoisotopic elements but all have odd atomic numbers, and even numbers of neutrons. Of the 10 radioisotopes of beryllium, the most stable are 10 Be with a half-life of 1.387(12) million years [nb 1 ...
Within the cores of stars, beryllium is depleted as it is fused into heavier elements. Beryllium constitutes about 0.0004 percent by mass of Earth's crust. The world's annual beryllium production of 220 tons is usually manufactured by extraction from the mineral beryl, a difficult process because beryllium bonds strongly to oxygen.
Beryllium alloys are used for mechanical parts when stiffness, light weight, and dimensional stability are required over a wide temperature range. [69] [70] Beryllium-9 is used in small-scale neutron sources that use the reaction 9 Be + 4 He (α) → 12 C + 1 n, the reaction used by James Chadwick when he discovered the neutron.
A beryllium ion has been trapped in a superposed state. [4] A double slit experiment has been performed with molecules as large as buckyballs and functionalized oligoporphyrins with up to 2000 atoms. [5] [6] Molecules with masses exceeding 10,000 and composed of over 810 atoms have successfully been superposed [7]
NA62 experimental area at CERN that fires high-energy protons from the Super Proton Synchrotron (SPS) into a stationary beryllium target.. Rutherford's gold foil experiment that led to the discovery that mass and positive charge of an atom was concentrated in a small nucleus was probably the first fixed-target experiment.
Beryllium-10 (10 Be) is a radioactive isotope of beryllium. It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen. [ 3 ] [ 4 ] [ 5 ] Beryllium-10 has a half-life of 1.39 × 10 6 years, [ 6 ] [ 7 ] and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV.
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.