Pre-Lab - Atomic Spectra                     Name

 

  1. How do you change the tubes in this lab?

 

 

 

 

 

 

                                                             
  1. The wavelength of visible light has the approximate range of _____ to _____ nm.        (109 nm = 1 meter)

 

 

  1. Which is the best value for the wavelength of red?
    1. 656 nm
    2. 486 nm
    3. 434 nm
    4. 365 nm

 

 

  1. The value of the Rydberg constant (to 5 sig figs) obtained from NIST, physics.nist.gov, is ____________.

 

 

  1. If the grating constant is given as 600 lines per mm, what is “d” (meters per line)?
    1. (1 / 600) m
    2. (1 / 0.6) m
    3. (1 / 600,000) m

 

 
  1. Fill in the following table (4 sig figs)    (Show work for Violet)

     

Balmer (ending on 2nd energy state)

 

Color

n

λ (nm)

red

3

656.2

“R” is the Rydberg Constant

 

4

 

 

5

 

violet

6

 

limit

∞

 

 

(#6 & 7 are double value questions)     

 

m λ = “d” sinθ

 

d:  inverse of the grating constant in meters  (#5)

θ:  degrees from central axis passing through the scope

 

Please fill in the following table using the above formula and value of “d”.

 
  1.  

 

 λ (nm)

(from #6)

θ for

m = 1

θ for

m = 2

Show work for 1st order violet (m = 1)

Red

 

 

 

Green

 

 

 

Blue

 

 

 

Violet

 

 

 

 

LineFit

1/λ    =  -R  1/ni2    + R/4

y       =   m    x      +   b       

 

  1. The lab asks you to plot 1/λ  versus  1/ni2.  From this graph, how would you calculate the Rydberg Constant?

(answer must be in the form of expressions ONLY)