Question

What is the energy released in this β + nuclear reaction 22 11 N a → 22 10 N e + 0 1 e ? (The atomic mass of 22 N a is 21.994436 u and that of 22 N e is 21.991385 u)

this answer is wrong 2.842 MeV or 1.74 or 2.33 is all wrong please only do it if you know how to

Answer 1

This is a positron emission. Note that, here we need to account for an extra electron

so,

mass defect is given as

m = m_parent - m_daughter - 2 * m_electron

m = 21.994436 u - 21.991385 u - 2 * 0.00054858

m = 1.95384e-3 u

so,

Q = m * 931.5 MeV / u

Q = 1.82 MeV