What is q value of nuclear reaction

\( \newcommand\] \[P = 2.85 J/s\] \[P = 2.85 W\] Beta Decay \(\ce\) is unstable. How will it decay? Calculate the Q value for this decay. In addition to alpha decay, which typically occurs only for very large nuclei, another possible nuclear transformation involves the spontaneous transformation of a proton into a neutron, or vice-versa. There are actually three different decay processes that involve this type of transformation, which is governed by the weak force. These decays are generically referred to as beta decay. \(\Beta^-\) Decay Beta-minus decay involves the transformation of a neutron into a proton, electron, and anti-neutrino: \[ n \Rightarrow p^+ + e^- + \bar)c^2\] \(\Beta^+\) Decay Beta-plus decay involves the transformation of a proton into a neutron, positron, and neutrino: \[ p^+ \Rightarrow n + e^+ + v\] This process can only occur inside the nucleus. Generically, beta-plus decay can be written as \[_Z^AX\Rightarrow _ - 2m_e)c^2\] Electron Capture Electron capture involves a proton in the nucleus absorbing an inner shell electron: \[ p^+ + e^- \Rightarrow n+v\] Generically, electron capture can be written as \[ _Z^A X + e^- \Rightarrow _] Therefore, 81Kr will decay via electron capture, and release 0.281 MeV of energy per decay. If more than one decay involves a positive Q, the one that releases the most energy will typically dominate. The exception to this rule involves electron capture. Both beta-plus and beta-minus, if allowed, always dominate electron ...

Beta decay or β decay represents the disintegration of a parent nucleus to a daughter through the emission of the beta particle. This transition ( β – decay) can be characterized as:   Beta Decay – Q-value In nuclear and particle physics the energetics of nuclear reactions is determined by the Q-value of that reaction. The Q-value of the reaction is defined as the difference between the sum of the rest masses of the initial reactants and the sum of the masses of the final products, in energy units (usually in MeV). Consider a typical reaction, in which the projectile a and the target A gives place to two products, B and b. This can also be expressed in the notation that we used so far, a + A → B + b, or even in a more compact notation, A(a,b)B. See also: The Q-value of this reaction is given by: Q = [ma + mA – (mb + mB)]c 2 When describing beta decay (reaction without projectile), the disintegrating nucleus is usually referred to as the parent nucleus and the nucleus remaining after the event as the daughter nucleus. The emission of a beta particle, either an electron, β –, or a positron, β +, changes the atomic number of the nucleus without affecting its mass number. The total rest mass of the daughter nucleus and of the nuclear radiation released in a beta disintegration, m Daughter + m Radiation, is always less than that of the parent nucleus, m parent. The mass-energy difference, Q = [m parent – (m Daughter + m Radiation)]c 2 appears as the disintegration energy, ...

Calculation and measurement of energy By the method of closed energy cycles, it is possible to use measured radioactive-energy-release ( Q) values for In this cycle, energies from two of the alpha decays and one beta decay are measurable. The unmeasured beta-decay energy for bismuth-211, Q β−(Bi), is readily calculated because Q values around the cycle to be zero. Thus, Q β−(Bi) + 7.59 − 1.43 − 6.75 = 0. Solving this equation gives Q β−(Bi) = 0.59 MeV. This calculation by closed energy cycles can be extended from stable lead-207 back up the chain of alpha and beta decays to its natural A by 4, and beta decay does not change A, closed α−β-cycle calculations based on lead-207 can link up only those nuclei with mass numbers of the general type A = 4 n + 3, in which n is an integer. Another, the 4 n series, has as its natural precursor thorium-232 and its stable end product lead-208. Another, the 4 n + 2 series, has uranium-238 as its natural precursor and lead-206 as its end product. In early research on natural radioactivity, the classification of X 1, the isomers of protactinium-234 as U X 2 and U Z, uranium-234 as U II, and so forth. These original symbols and names are occasionally encountered in more recent literature but are mainly of historical interest. The remaining 4 n + 1 series is not naturally occurring but To extend the knowledge of nuclear binding energies, it is clearly necessary to make measurements to supplement the radioactive-decay energy cycles. In part, ...

Return to ITER Power Facts Main Page By Steven B. Krivit April 8, 2022 Explained in this article: — The difference between Q scientific and Q engineering — The difference between reaction gain and reactor gain — The difference between scientific breakeven and engineering breakeven — The difference between Fusion Power and Fusion Power — The fusion term “scientifically feasible” — The relevance of experimental fusion results to possible commercial fusion prospects James McKenzie was the vice president for business at the U.K. Institute of Physics from 2016 to 2020. In March 2022, McKenzie wrote an article in Physics World enthusiastically promoting public support of fusion. He explained why: Once you achieve fusion, you need to generate more energy than you put in, so that the ratio Q > 1. But a breakeven result has so far never been achieved by a fusion reactor here on Earth. In fact, what you really want is a Q between 5 and 10 so that your reactor produces a useful amount of power. Full stop. A reactor, like ITER or SPARC, designed to reach a “Q” of 10, cannot produce a useful amount of power. Fusion experts have had a long history of creating misunderstandings among people who are not experts in the field. McKenzie was only the latest casualty. Even Daniel Clery, Science magazine reporter and author of a popular book on fusion, wrote just a few days earlier that “ITER is designed to show net energy output can be achieved.” In this explainer, I will clarify the various m...

The Q value of a nuclear reaction, A + b → C + d, is defined by Q = [ mA + mb ] - [ mC + md ] where, the masses refer to the respective nuclei. Determine from the given data the Q - value of the following reactions and state whether the reactions are exothermic or endothermic.(i) ^11H + ^13H → ^21H + ^21H (ii) ^126C + ^126C → ^2010Ne + ^42He Atomic masses are given to be m (^21H) = 2.014102 u m (^31H) = 3.016049 u m (^126C) = 12.000000 u m (^2010Ne) = 19.992439 u The Q value of a nuclear reaction, A + b → C + d, is defined by Q = [ m A ​ + m b ​ ] − [ m C ​ + m d ​ ] where, the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic. (i) 1 1 ​ H + 3 1 ​ H → 1 2 ​ H + 1 2 ​ H (ii) 6 1 2 ​ C + 6 1 2 ​ C → 1 0 2 0 ​ N e + 2 4 ​ H e Atomic masses are given to be m ( 1 2 ​ H ) = 2 . 0 1 4 1 0 2 u m ( 1 3 ​ H ) = 3 . 0 1 6 0 4 9 u m ( 6 1 2 ​ C ) = 1 2 . 0 0 0 0 0 0 u m ( 1 0 2 0 ​ N e ) = 1 9 . 9 9 2 4 3 9 u (i) 1 1 ​ H + 1 3 ​ H → 1 2 ​ H + 1 2 ​ H Q = [ m 1 1 ​ H ​ + m 1 3 ​ H ​ ] − [ m 1 2 ​ ​ + m 1 2 ​ H ​ ] Q = 1 . 0 0 7 5 8 + 3 . 0 1 6 0 4 9 − [ 2 . 0 1 4 1 0 2 + 2 . 0 1 4 1 0 2 ] Q = − 0 . 0 0 4 6 u Since, Q is negative, some mass is converted into energy. Hence, the reaction is endothermic. (ii) 6 1 2 ​ C + 6 1 2 ​ C → 1 0 2 0 ​ N e + 2 4 ​ H e Q = [ m 6 1 2 ​ C ​ + m 6 1 2 ​ C ​ ] − [ m 1 0 2 0 ​ N e ​ + m 2 4 ​ H e ​ ] Q = 1 2 . 0 0 0 0 0 0 + 1 2 . 0 0 0 0...