(Helium-4 nucleus with masses in SI units)

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

(Helium-4 nucleus with masses in SI units) (i) The rest mass of a free proton is

m_p = 1.67262\times10^{-27}\,\text{kg}

and that of a free neutron is

m_n = 1.67493\times10^{-27}\,\text{kg}

. The mass of a

_2^4\!He

nucleus (alpha particle) is

M_{\alpha}=6.64466\times10^{-27}\,\text{kg}

. Calculate its mass defect in kilograms. (ii) Using

c = 3.00\times10^{8}\,\text{m s}^{-1}

, compute the binding energy of the

_2^4\!He

nucleus in joules and then convert your answer to mega-electron-volts. (iii) Find the binding energy per nucleon for

_2^4\!He

in MeV.