Question

Calculate the mass defect and binding energy in

${}_8^{7}Li$ (isotopic mass = 7.01436 amu).

• A. 42.6 MeV
• B. 22.6 MeV
• C. 46.6 MeV
• D. None of these

Answer 1

Answer: (A)

42.6 MeV

Binding energy is calculated as follows:

$E=\Delta E=\Delta m\times 931$ MeV (as $1$ amu $=931$ MeV)

Here,

$\Delta m=(3m_p+4m_n)–massofL{i}^7$

$=(3\times 1.00759+4\times 1.008898)–7.01436$

$=0.04716$

$\Delta E=0.04716\times 931=42.6$ MeV