Question

Calculate the Q-value of the fusion reaction ⁴He + ⁴He = ⁸Be. Is such a fusion energetically favourable? Atomic mass of ⁸Be is 8.0053 u and that of ⁴He is 4.0026 u.

(Use Mass of proton m_p = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron m_n = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c²,1 u = 931 MeV/c².)

Answer 1

Given:-

Atomic mass of ⁸Be = 8.0053 u
Atomic mass of ⁴He = 4.0026 u

Required Q-value = `(2 xx 4.0026 - 8.0053) c^2`

`= 0.0001 xx 931  "MeV"`

`= 0.0001 xx 931 xx 10^6  "eV"`

= 93.1  KeV

No, such reaction is not favourable.