Question

A certain mass of hydrogen is changed to helium by the process of fusion. The mass defect in fusion reaction is 0.02866 u. The energy liberated per u is (1u = 931 MeV)

(1) 13.35 MeV

(2) 2.67 MeV

(3) 26.7 MeV

(4) 6.67 MeV

Answer 1

(4) 6.67 MeV

Total mass defect Δ m in the fusion reaction is 0.02866 u 

Total energy released = 0.02866×931 MeV 

Since 4 nuclei of hydrogen fuse to form a helium nucleus.

∴ Energy realeased per nucleus = 0.02866 x 931 / 4 = 6.67 MeV