Respuesta :

Answer:

The longest wavelength observed in the Balmer series of the H atom spectrum is 656.3 nm.

The shortest wavelength observed in the Balmer series of the H atom spectrum is 364.6 nm.

Explanation:

Using Rydberg's Equation:

[tex]\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )[/tex]

Where,

[tex]\lambda[/tex] = Wavelength of radiation

[tex]R_H[/tex] = Rydberg's Constant

[tex]n_f[/tex] = Higher energy level

[tex]n_i[/tex]= Lower energy level

[tex]\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )[/tex]

For wavelength to be longest, energy would be minimum, i.e the electron  will jump from third level to second level  :

[tex]n_f[/tex] = Higher energy level = [tex]3[/tex]  

[tex]n_i[/tex]= Lower energy level = 2 (Balmer series)

Putting the values, in above equation, we get

[tex]\frac{1}{\lambda_{Balmer}}=R_H\left(\frac{1}{2^2}-\frac{1}{3^2} \right )[/tex]

[tex]\lambda_{Balmer}=\frac{36}{5R_H}[/tex]

[tex]\lambda_{Balmer}=\frac{36}{5\times 1.097\times 10^7 m^-1}}=6.563\times 10^{-7} m=656.3 nm[/tex]

[tex]1 m =10^9 nm[/tex]

The longest wavelength observed in the Balmer series of the H atom spectrum is 656.3 nm.

For wavelength to be shortest, energy would be maximum, i.e the electron  will from infinite level to second level. :

[tex]n_f[/tex] = Higher energy level = [tex]\infty[/tex]  

[tex]n_i[/tex]= Lower energy level = 2 (Balmer series)

Putting the values, in above equation, we get

[tex]\frac{1}{\lambda_{Balmer}}=R_H\left(\frac{1}{2^2}-\frac{1}{\infty^2} \right )[/tex]

[tex]\lambda_{Balmer}=\frac{4}{R_H}[/tex]

[tex]=\frac{4}{1.097\times 10^7 m^-1}=3.646\times 10^{-7} m=364.6 nm[/tex]

The shortest wavelength observed in the Balmer series of the H atom spectrum is 364.6 nm.