- #1
scorpa
- 367
- 1
Hello Everyone,
I've been doing some physics homework and have gotten all but two of the questions. They are on electron transitions.
#1) In a hypothetical hyrogen like atom the energy of the second energy level is -13.6eV. Calculate the momentum of the electron in the third energy level of this atom.
En = (1/3^2)(13.6) = 1.51 ev
1.51 eV = 2.42 x 10^-19 J
Ek = (1/2)mv^2
square root of (2.42x10^-19J/(0.5 x 9.11 x 10^-31) )
v = 7.3 x 10^5 m/s
p = mv
p = (9.11x10^-31kg)(7.3x10^5m/s) = 6.7 x 10^-25 kg*m/s
The answer should be 1.34 x 10^-24 kg*m/s
I have no idea what I've done wrong
#2) A spectra line in the hydrogen bright line spectra (NOTE: visible region) passes perpendicularily through a diffraction grating (d= 5.00x10^-6m). This spectra line produces a first order maximum at an angle of 4.97 degrees. What is the transition of the elctron that produces this spectra line?
wavelength = (5.00 x 10^-6m)(sin4.97)/1 = 4.33 x 10^-7m
Using Rydberg's equation I subsituted and manipulated and got:
(1/4) - ((1/4.33x10^-7)/1.1x 10^7) then I took the square root of that and got 0.2 which definitely isn't right.
The answer should be 5 to 2. Once again I don't know where I've gone wrong.
Any help is greatly appreciated, thanks in advance!
I've been doing some physics homework and have gotten all but two of the questions. They are on electron transitions.
#1) In a hypothetical hyrogen like atom the energy of the second energy level is -13.6eV. Calculate the momentum of the electron in the third energy level of this atom.
En = (1/3^2)(13.6) = 1.51 ev
1.51 eV = 2.42 x 10^-19 J
Ek = (1/2)mv^2
square root of (2.42x10^-19J/(0.5 x 9.11 x 10^-31) )
v = 7.3 x 10^5 m/s
p = mv
p = (9.11x10^-31kg)(7.3x10^5m/s) = 6.7 x 10^-25 kg*m/s
The answer should be 1.34 x 10^-24 kg*m/s
I have no idea what I've done wrong
#2) A spectra line in the hydrogen bright line spectra (NOTE: visible region) passes perpendicularily through a diffraction grating (d= 5.00x10^-6m). This spectra line produces a first order maximum at an angle of 4.97 degrees. What is the transition of the elctron that produces this spectra line?
wavelength = (5.00 x 10^-6m)(sin4.97)/1 = 4.33 x 10^-7m
Using Rydberg's equation I subsituted and manipulated and got:
(1/4) - ((1/4.33x10^-7)/1.1x 10^7) then I took the square root of that and got 0.2 which definitely isn't right.
The answer should be 5 to 2. Once again I don't know where I've gone wrong.
Any help is greatly appreciated, thanks in advance!