In stellar interiors four hydrogen nuclei (protons) can fuse to form one nucleus

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

Problem

In stellar interiors four hydrogen nuclei (protons) can fuse to form one

^4\!\mathrm{He}

nucleus. Ignore the emission of any other particles and take the following nuclear masses:

\mathrm{m_p}=1.00727\,\text{u}

, mass of

^4\!\mathrm{He}

nucleus

=4.00150\,\text{u}

. Avogadro constant

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

1\,\text{u}=931.5\,\text{MeV}/c^{2}

. (a) Calculate the mass defect for the fusion of four protons into one

^4\!\mathrm{He}

nucleus. (b) Determine the energy released per fusion event in MeV. (c) Estimate the total energy released when

1.0\,\text{g}

of hydrogen is completely converted into helium by this process.