Nuclear reactions mass defect

Energetics of Nuclear Reactions, Mass Defect, and Nuclear Binding Energy... 

Note that Q is an important quantity for nuclear reactions. If the masses of both the products and reactants are known (Appendix B), the Q value can be calculated using the mass defects, A, as ... 

Mass Defect The amount of mass of the particles involved in the nuclear reaction that is converted to energy. 

The energy Q related to the nuclear reaction is determined from the differences in the masses M of the reactants and the products converted to million electron volts so that, for the example reaction, Q = [M2 ai + Mip — ( 2751 + Min)] x 931.5. The masses are expressed in atomic mass units as neutral atoms and the conversion factor is 931.5, in units of million electron volts per atomic mass unit. A more convenient calculation is to use, instead of M, the commonly tabulated mass excess or defect A. The quantity A is the atomic mass minus the mass number (A) for the nuclide, expressed in million electron volts. These quantities for the individual reactants and products can be substituted in the calculation of Q. For this example, Q = A( Al) - - A( H) — A( Si) — A( n) = —17.194 - -7.289 -I- 12.385 - 8.071 MeV = -5.591 MeV. The negative value of Q shows that the kinetic energy of the proton is required for the reaction. 

Knowledge of nuclear forces is thus in one way very definite. The mass defects, which can be determined with considerable precision, yield quite reliable information about the relative energies of formation from possible eonstitutents. The quantitative application of the equation c Am — AE is well illustrated by the example of the reaction occurring when a fast proton causes the disintegration of... 

Reactions of this type also release a lot of energy. Where does the energy come from Well, if you make very accurate measurement of the masses of all the atoms and subatomic particles you start with and all the atoms and subatomic particles you end up with, and then compare the two, you find that there s some ""missing mass. Matter disappears during the nuclear reaction. This loss of matter is called the mass defect The missing matter is converted into energy. 

The nuclear binding energy is the energy equivalent to the mass defect. E = mc is used to determine the energy liberated in a nuclear reaction. 

Section 21.6 The energy produced in nuclear reactions is accompanied by measurable tosses of mass in accordance wilh Einstein s relationship, AE = c Am. The difference in mass between nuclei and the nucleons of which Ihey are composed is known as Ihe mass defect. The mass defect of a nuclide makes it possible to calculate its nuclear binding energy, Ihe energy required to separate Ihe nucleus into individual nucleons. Energy is produced when heavy nuclei split (fission) and when light nuclei fuse (fusion). 

Radioactive cobalt-60 is used to study defects in vitamin B12 absorption because cobalt is the metallic atom at the center of the vitamin molecule. The nuclear synthesis of this cobalt isotope involves a three-step process. The overall reaction is iron-58 reacting with two neutrons to produce cobalt-60 along with the emission of another particle. What particle is emitted in this nuclear synthesis What is the binding energy in J per nucleon for the cobalt-60 nucleus (atomic masses Co = 59.9338 amu ... 

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