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Bromine-82
Bromine (35Br) has two stable isotopes, 79Br and 81Br, and 32 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours. List of isotopes , - , 68Br , style="text-align:right" , 35 , style="text-align:right" , 33 , 67.95836(28)# , ~50 ns , p , 67Se , 3+# , , , - , 69Br , style="text-align:right" , 35 , style="text-align:right" , 34 , 68.95011(11)# , 99.9%) , 72Br , rowspan=2, 1− , rowspan=2, , rowspan=2, , - , β+ (<0.1%) , 72Se , - , 73Br , style="text-align:right" , 35 , style="text-align:right" , 38 , 72.93169(5) , 3.4(2) min , β+ , 73Se , 1/2− , , , - , 74Br , style="text-align:right" , 35 , style="text-align:right" , 39 , 73.929891(16) , 25.4(3) min , β+ , 74Se , (0−) , , , - , style="text-indent:1em" , 74mBr , colspan="3" style="text-indent:2em" , 13.58(21) keV , 46(2) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine
Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek (bromos) meaning "stench", referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a native element in nature but it occurs in colourless soluble crystalline mineral halide salts, analogous to table salt. In fact, bromine and all the halogens are so reactive that they form bonds in pairs—never in single atoms. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its accumulation in the oceans. Commercial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely, non-exponential) decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, ''half-life period'', dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to ''half-life'' in the early 1950s. Rutherford applied the principle of a radioactive element's half-life in studies of age determination of rocks by measuring the decay period of radium to lead-206. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Decay
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For example, beta decay of a neutron transforms it into a proton by the emission of an electron accompanied by an antineutrino; or, conversely a proton is converted into a neutron by the emission of a positron with a neutrino in so-called ''positron emission''. Neither the beta particle nor its associated (anti-)neutrino exist within the nucleus prior to beta decay, but are created in the decay process. By this process, unstable atoms obtain a more stable ratio of protons to neutrons. The probability of a nuclide decaying due to beta and other forms of decay is determined by its nuclear binding energy. The binding energies of all existing nuclides form what is called the nuclear band or valley of stability. For either electron or positron em ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomeric Transition
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have half-lives 100 to 1000 times longer than the half-lives of the excited nuclear states that decay with a "prompt" half life (ordinarily on the order of 10−12 seconds). The term "metastable" is usually restricted to isomers with half-lives of 10−9 seconds or longer. Some references recommend 5 × 10−9 seconds to distinguish the metastable half life from the normal "prompt" gamma-emission half-life. Occasionally the half-lives are far longer than this and can last minutes, hours, or years. For example, the nuclear isomer survives so long (at least 1015 years) that it has never been observed to decay spontaneously. The half-life of a nuclear isomer can even exceed that of the ground state of the same nuclide, as shown by as well as , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Emission
Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a nucleus. It occurs in the most neutron-rich/proton-deficient nuclides, and also from excited states of other nuclides as in photoneutron emission and beta-delayed neutron emission. As only a neutron is lost by this process the number of protons remains unchanged, and an atom does not become an atom of a different element, but a different isotope of the same element. Neutrons are also produced in the spontaneous and induced fission of certain heavy nuclides. Spontaneous neutron emission As a consequence of the Pauli exclusion principle, nuclei with an excess of protons or neutrons have a higher average energy per nucleon. Nuclei with a sufficient excess of neutrons have a greater energy than the combination of a free neutron and a nucleus with one less neutron, and therefore can decay by neutron emission. Nuclei which can decay by this process are described as lying beyond the neutron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotopes Of Bromine
Bromine (35Br) has two stable isotopes, 79Br and 81Br, and 32 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours. List of isotopes , - , 68Br , style="text-align:right" , 35 , style="text-align:right" , 33 , 67.95836(28)# , ~50 ns , p , 67Se , 3+# , , , - , 69Br , style="text-align:right" , 35 , style="text-align:right" , 34 , 68.95011(11)# , 99.9%) , 72Br , rowspan=2, 1− , rowspan=2, , rowspan=2, , - , β+ (<0.1%) , 72Se , - , 73Br , style="text-align:right" , 35 , style="text-align:right" , 38 , 72.93169(5) , 3.4(2) min , β+ , 73Se , 1/2− , , , - , 74Br , style="text-align:right" , 35 , style="text-align:right" , 39 , 73.929891(16) , 25.4(3) min , β+ , 74Se , (0−) , , , - , style="text-indent:1em" , 74mBr , colspan="3" style="text-indent:2em" , 13.58(21) keV , 46(2) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
