Answer: [tex]0.98\times 10^{-7}m[/tex]
Explanation:
For calculating wavelength, when the electron will jump from n=4 to n= 1
Using Rydberg's Equation: for hydrogen atom
[tex]\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )\times Z^2[/tex]
Where,
[tex]\lambda[/tex] = Wavelength of radiation = ?
[tex]R_H[/tex] = Rydberg's Constant = [tex]1.097\times 1067m[/tex]
[tex]n_f[/tex] = Higher energy level = 4
[tex]n_i[/tex]= Lower energy level = 1
Z= atomic number = 1 (for hydrogen)
Putting the values, in above equation, we get
[tex]\frac{1}{\lambda}=1.097\times 10^7\left(\frac{1}{1^2}-\frac{1}{4^2} \right )\times 1^2[/tex]
[tex]\lambda=0.98\times 10^{-7}m[/tex]
Thus the wavelength of the photon emitted will be [tex]0.98\times 10^{-7}m[/tex]