Question: How much energy is lost (produced) or gained when Co-60 undergoes a beta decay? Mass of Co-60 is 59.9338 g, Mass of Ni-60 is 59.9308 g.
Solution:
m = 59.9308 g - 59.9338 g = -0.003 g = -0.003 x 10-3 kg
E = mc2, where m = expressed in Kg, and c = 3.00 x 108 m/s
E = -0.003 x 10-3 kg (3.00 x 108m/s)2 = -3 x 10-6 kg x 9.00 x 1016 kg.m2/s2 = -27 x 1010 kg.m2/s2 = - 2.7 x 1011kg.m2/s2 = -2.7 x 1011J = Energy produced = -6.45 x 1010 calories
(1J = 0.2388 calorie; 1calorie = 4.1868 J)
N.B: Notice the huge amount of energy produced by just 0.003 g of matter!