Question

What is the binding energy of oxygen?

Answer 1

Step 1: Calculating the number of neutrons, protons, and electrons:

The isotope ${}_8{}^{16}\mathrm{O}$ contains $8$ protons, $8$ neutrons and $8$ electrons.

Step 2: Calculating the actual mass:
The actual mass of the nucleus of ${}_8{}^{16}\mathrm{O}=16$ - Mass of 8 electrons
$=16-8\times 0.0005486=159956\mathrm{amu}$
Mass of the nucleus of ${}_8{}^{16}\mathrm{O}=$ Mass of 8 protons + Mass of 8 neutrons
$=8\times 1.00757+8\times 1,00893=16.132\mathrm{amu}$

step 3: Calculating the mass defect:
Mass defect $$\begin{gathered} =(16.132-15.9956) \\ =0.1364\mathrm{amu} \end{gathered}$$

Hence, the binding energy of oxygen$=0.1364\times 931=127MeV.$