Question

1. Given the following information:
Proton mass = 1.0078 u
Neutron mass = 1.0087 u
Mass of 226/88 Ra = 226.0244 u
a) Determine the mass defect for this isotope.
b) Determine the binding energy for nucleon for this isotope.
c) Radium-88 undergoes alpha decay via the following equation:

226/88Ra = 222/86Rn + 4/2He + Q
If the mass of the radon-86 isotope is 222.0165 u and the mass of the helium-
4 isotope is 4.0026 u, how much energy, in million electron volts, is
associated with quantity Q?

Note: Slash denotates bottom and = denotates arrow.

Answer 1

a) The mass defect of the isotope is (mass of the nucleons) minus (total mass of the nucleus)

The mass defect in kg is

b) The binding energy is the mass defected converted into energy

Note that 1 u is equivalent to 931.5 MeV.

Therefore the binding energy is

c) The Q value of the reaction is

The answer in MeV is