What is the binding energy of the helium atom whose mass defect is 0.030377 u?  

m = 0.030377 u ´ 1.661 ´ 10^-27 kg = 5.046 ´ 10^-27 kg (P)

E = mc² = 5.046 ´ 10-27 kg ´ (3 ´ 10⁸)² = 4.541 ´ 10^-12 J (P)