Energy per mole for a nucleus

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

Problem

Energy per mole for a

^4\mathrm{He}

nucleus. Use the data: mass of proton

m_p=1.007276\,\mathrm{u}

; mass of neutron

m_n=1.008665\,\mathrm{u}

; atomic mass of

^4\mathrm{He}=4.002603\,\mathrm{u}

; Avogadro number

N_A=6.022\times10^{23}\,\mathrm{mol}^{-1}

;

1\,\mathrm{u}=931.5\,\mathrm{MeV}

; and

1\,\mathrm{eV}=1.6\times10^{-19}\,\mathrm{J}

. (i) Compute the mass defect for one

^4\mathrm{He}

nucleus. (ii) Find the binding energy of one

^4\mathrm{He}

nucleus in joule. (iii) Hence calculate the total binding energy released, in kJ, when one mole of

^4\mathrm{He}

nuclei is formed from free protons and neutrons.