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Boron-7
Boron (5B) naturally occurs as isotopes and , the latter of which makes up about 80% of natural boron. There are 13 radioisotopes that have been discovered, with mass numbers from 7 to 21, all with short half-lives, the longest being that of , with a half-life of only and with a half-life of . All other isotopes have half-lives shorter than . Those isotopes with mass below 10 decay into helium (via short-lived isotopes of beryllium for and ) while those with mass above 11 mostly become carbon. List of isotopes , - , ?This isotope has not yet been observed; given data is inferred or estimated from periodic trends. , style="text-align:center" , 5 , style="text-align:center" , 1 , , p-unstable , 2p? , ? , 2−# , , , - , , style="text-align:center" , 5 , style="text-align:center" , 2 , , [] , p , Subsequently decays by double proton emission to for a net reaction of → + 3 , (3/2−) , , , - , Has 1 halo nucleus, halo proton , style="text ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the '' boron group'' it has three valence electrons for forming covalent bonds, resulting in many compounds such as boric acid, the mineral sodium borate, and the ultra-hard crystals of boron carbide and boron nitride. Boron is synthesized entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, so it is a low-abundance element in the Solar System and in the Earth's crust. It constitutes about 0.001 percent by weight of Earth's crust. It is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. These are mined industrially as evaporites, such as borax and kernite. The largest known deposits are in Turkey, the largest producer of boron minerals. Elemental boron is a meta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
