The wavelength of K-x-ray from copper is 1.377 ｘ 10⁻¹⁰ m. What is the energy difference between the two levels from which this transition results? (Ans: 9.03 keV)


Given:


Wavelength = λ = 1.377 ｘ 10⁻¹⁰ m

∴ Plank's Constant = h =  6.62 ｘ 10⁻³⁴ m² kg s⁻¹

∴ Velocity of light  = c = 3 ｘ 10⁸ m s⁻¹



To Find:


Energy Difference = ΔE = ?


Solution:

We know that

ΔE = h f 

we also know that 

v = f λ

⇒ f = `\frac {c}{λ}`

Thus,

ΔE = `\frac {hc}{λ}`


by putting values

ΔE =`\frac {6.62 ｘ 10⁻³⁴ m² kg s⁻¹ ｘ 3 ｘ 10⁸ m s⁻¹}{1.377 ｘ 10⁻¹⁰ m}`

ΔE = `\frac {19.86 ｘ 10⁻²⁶ m³ kg s⁻² }{1.377 ｘ 10⁻¹⁰ m}`

ΔE =  14.423 ｘ 10⁻¹⁶ J

expressing in eV  we have 

K.E = `\frac {14.42 ｘ 10⁻¹⁶ }{1.6 ｘ 10⁻¹⁹ }` eV

K.E = 9.014375 ï½˜ 10³ eV

K.E = 9.02 keV ----------------Ans.



Similar Questions:



************************************

Shortcut Links For 


1. Website for School and College Level Physics   
2. Website for School and College Level Mathematics  
3. Website for Single National Curriculum Pakistan - All Subjects Notes 

© 2022-Onwards by Academic Skills and Knowledge (ASK)     

Note:  Write me in the comment box below for any query and also Share this information with your class-fellows and friends.