Calculate the Q-value of the fusion reaction
4He + 4He = 8Be.
Is such a fusion energetically favorable? Atomic mass of 8Be is 8.0053 u and that of 4He is 4.0026 u.
4He + 4He = 8Be.
Q value= [2m(4He)- m(8Be)]u
= [2×4.0026 – 8.0053] × 931MeV
=-93.1KeV
Negative sign indicates that the energy has to be provided to proceed this reaction. So, this fusion is not favorable.