Question

1.Li-7 (atomic mass = 7.016003 amu) find the Binding energy per nucleon = ____ MeV/nucleon

Answer 1

Binding energy = [mass of individual neutrons and protons] - [mass of nucleus]

Li-7 is made of 3 protons, 4 neutrons and 3 electrons (if neutral).

The mass of 3 protons by themselves should be

3 x 1.00727646677 = 3.0218294

The mass of 4 neutrons by themselves should be

4 x 1.0086649156 = 4.0346597

The sum of nucleons = 7.056489 amu

Li-7 (atomic mass = 7.016003 amu)

The difference is around 0.0405 amu = 37.7 MeV (using 931.494 MeV per amu).

Answer is 37.7 MeV