In: Chemistry
Calculate the nuclear binding energy in mega-electronvolts (MeV) per nucleon for 179Hf if its nuclear mass is 178.946 amu.
Calculate the nuclear binding energy in mega-electronvolts (MeV) per nucleon for 179Hf if its nuclear mass is 178.946 amu.
The atomic mass of 179/72 Hf is 178.946 amu. Calculate the nuclear binding energy of this
nucleus and the corresponding nuclear binding energy per nucleon
Mass number = 179
No. of protons = 72, then
Neutrons = Mass number – proton number = 72 protons and 179-72= 107 neutrons are present
Mass of proton = 1.007316
Mass of neutrón = 1.008701
Total mass = 72*1.007316+ 107*1.008665 = 180.453907 amu
The mass defect:
180.453907-178.946 = -1.507907 amu
Mass = 1.507907 /(6.022*10^23) = 2.503*10^-24 g or -2.503*10^-27 kg
Energy released (Einstein E = mC^2)
E = m*C^2 = -2.503*10^-27 * (3*10^8)^2 = -2.2527*10^-10 J
Nuclear binding energy = E = -2.2527*10^-10 J
Nuclear binding energy per nucleon
Nucleon = neutron + protons = 179
E per nucleon = E / nucleon =(2.2527*10^-10)/( 179) = 1.258*10^-12 J/nucleon
change to meV
1 J = 6.242*10^12 MeV
1.258*10^-12 J --> x
x = ( 6.242*10^12)(1.258*10^-12) = 7.852436 MeV / nucleon