The neutral atomic mass difference between a possible β⁺ parent and daughter is 0.0020 u. Take 1 u·c² = 931.5 MeV and mₑc² = 0.511 MeV. The kinetic energy available to the decay products after accounting for positron creation is closest to:
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Question

The neutral atomic mass difference between a possible β⁺ parent and daughter is 0.0020 u. Take 1 u·c² = 931.5 MeV and mₑc² = 0.511 MeV. The kinetic energy available to the decay products after accounting for positron creation is closest to:

Options

G1 Physics · Accepted Answer

Mass-energy difference from atomic masses: ΔE = 0.0020×931.5 = 1.863 MeV. For β⁺-decay, neutral atomic masses require subtraction of two electron rest energies: 2mₑc² = 1.022 MeV. Therefore, Q = 1.863−1.022 = 0.841 MeV. Hence the available kinetic energy is approximately 0.84 MeV. Correct option: A.