(a) Draw the energy level diagram for hydrogen atom. Mark the transitions corresponding to the series lying in the ultraviolet region, visible region…

Energy level diagram for hydrogen atom \(\displaystyle 1 \frac{1}{2}\) Transitions corresponding to ultraviolet region, visible region and infrared region \(\displaystyle \frac{1}{2}+\frac{1}{2}+\frac{1}{2}\)

Features of diagram

1. Binding energy per nucleon is practically independent of atomic number for nuclei of middle mass number ( \(\displaystyle 30<\mathrm{A}<170\) )

2. The curve has maximum of about $\displaystyle 8.75$ MeV for \(\displaystyle \mathrm{A}=56\) and has a value of $\displaystyle 7.6$ MeV for \(\displaystyle \mathrm{A}=238\)

3. Binding energy per nucleon is lower for both light nuclei ( \(\displaystyle \mathrm{A}<30\) ) and heavy nuclei \(\displaystyle (\mathrm{A}>170)\)

Two lighter nuclei fuse together to form heavier nuclei as the binding energy per nucleon of fused heavier nuclei is more than the binding energy per nucleon of the lighter nuclei. Thus the final system is more tightly bound