Finding n for Line Spectra with 400 nm Wavelength

  • Context: Undergrad 
  • Thread starter Thread starter pisay
  • Start date Start date
  • Tags Tags
    Line Spectra
Click For Summary
SUMMARY

The discussion centers on calculating the principal quantum number (n) for line spectra at a wavelength of 400 nm using the formula 1/W = R(1/4 - 1/n^2). The constant R is defined as 1.097e7. The calculated value of n is approximately 6.752, which is not an integer. The consensus is to round n to 7, as n must be an integer greater than zero. This adjustment yields a wavelength of 397 nm, confirming that n can indeed take values greater than 5.

PREREQUISITES
  • Understanding of quantum mechanics principles
  • Familiarity with the Rydberg formula for spectral lines
  • Basic algebra for manipulating equations
  • Knowledge of wavelength and its relationship to energy levels
NEXT STEPS
  • Study the Rydberg formula in detail to understand its applications
  • Explore quantum mechanics concepts related to energy levels in atoms
  • Learn about the significance of integer values in quantum numbers
  • Investigate the implications of rounding in scientific calculations
USEFUL FOR

Students and professionals in physics, particularly those studying atomic spectra, quantum mechanics, and anyone involved in calculations related to spectral lines.

pisay
Messages
4
Reaction score
0
I was given 400 nm. I was tasked to find n but i kept getting a value which is a not a integer. The value of n must be an integer right?

1/W = R(1/4 - 1/n^2)

manipulate

n=sqrt(4RW/RW-4)

where R=1.097e7

n=6.752

I am thinking to make n as 6. But are there values of n greater than 5?
 
Physics news on Phys.org
n can take any integer number(greater than zero), and since you got n=6.752, I would give the answer n=7.

n = 7 gives you W = 397nm ...
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 9 ·
Replies
9
Views
8K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K