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Zorluk: OrtaNuclear Fission and Nuclear Fusion
In a nuclear fusion process, two deuterium nuclei (\text{^{2}_{1}H}) fuse to form a helium-3 nucleus (\text{^{3}_{2}He}) and a neutron (\text{^{1}_{0}n}) according to the reaction equation:
\text{^{2}_{1}H} + \text{^{2}_{1}H} \rightarrow \text{^{3}_{2}He} + \text{^{1}_{0}n} + Q

Given the mass values:
- Mass of \text{^{2}_{1}H} = 2.0141\text{ u}
- Mass of \text{^{3}_{2}He} = 3.0160\text{ u}
- Mass of \text{^{1}_{0}n} = 1.0087\text{ u}

Using the conversion factor 1 u=931.5 MeV1\text{ u} = 931.5\text{ MeV}, what is the energy released (QQ) in this fusion reaction in MeV\text{MeV}?

Cevap: 3.26 MeV

Cevap

The total energy released (QQ) in the reaction is 3.26 MeV3.26\text{ MeV}.
The energy released in a nuclear fusion reaction is proportional to the decrease in total rest mass (mass defect). Summing the mass of two deuterium nuclei gives 4.0282 u4.0282\text{ u}, while the sum of the product masses (\text{^{3}_{2}He} and a neutron) is 4.0247 u4.0247\text{ u}. Subtracting these yields a mass defect of 0.0035 u0.0035\text{ u}. Multiplying 0.0035 u0.0035\text{ u} by 931.5 MeV/u931.5\text{ MeV/u} gives 3.26 MeV3.26\text{ MeV} of released energy.

Adım Adım Çözüm

1
Calculate the total initial mass of the reacting deuterium nuclei.
mreactants=2×2.0141 u=4.0282 um_{\text{reactants}} = 2 \times 2.0141\text{ u} = 4.0282\text{ u}
Two deuterium nuclei participate on the reactant side of the equation.
2
Calculate the total final mass of the products.
mproducts=3.0160 u+1.0087 u=4.0247 um_{\text{products}} = 3.0160\text{ u} + 1.0087\text{ u} = 4.0247\text{ u}
The reaction produces one helium-3 nucleus and one neutron.
3
Determine the mass defect (difference between reactant and product masses).
Δm=4.0282 u4.0247 u=0.0035 u\Delta m = 4.0282\text{ u} - 4.0247\text{ u} = 0.0035\text{ u}
The mass lost during fusion is converted into nuclear kinetic energy and radiation.
4
Convert the mass defect into energy in MeV using the conversion factor.
Q=0.0035 u×931.5 MeV/u=3.26025 MeV3.26 MeVQ = 0.0035\text{ u} \times 931.5\text{ MeV/u} = 3.26025\text{ MeV} \approx 3.26\text{ MeV}
Each atomic mass unit lost corresponds to 931.5 MeV931.5\text{ MeV} of energy.

Anahtar Kavram

Mass defect and energy release in nuclear fusion reactions (E=Δmc2E = \Delta m c^2)
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