Maximum Helium Fraction: Neutron Decay Time & Rest Mass Difference

[bolahab]

Suppose the neutron decay time n was 89 sec. AND the difference in
rest mass between neutron to proton, Qn, was 0.129 MeV. What would
the maximum Helium fraction, Yp, be?

 

[Astronuc]

Suppose the neutron decay time n was 89 sec. AND the difference in
rest mass between neutron to proton, Qn, was 0.129 MeV. What would
the maximum Helium fraction, Yp, be?

One needs to provide more information in order to solve this problem. A free neutron decays into a proton, electron and antineutrino, so the product of free neutron decay would be hydrogen. Or is the neutron decaying in a tritium atom, which then is transformed to He-3?

Or does one mean hydrogen rather than He?

 

[bolahab]

yes it is transformed into He-3, that was all the info from the question, but the rest info as it says in the book when it is transformed into He-3