× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
5
o
5
4
m
4
b
4
x
4
a
4
l
4
t
4
S
4
m
3
s
3
New Topic  
princess001 princess001
wrote...
Posts: 324
Rep: 3 0
10 years ago Edited: 10 years ago, princess001
1. Describe the pattern of intensity vs wavelength observed in blackbody experiments, and explain why these observations were in conflict with the predictions of classical physics. (3 marks)


2. What is the frequency of a 13.0 eV photon?

3. What is the wavelength of a 4.30 x 10^-19 J photon?
Read 3682 times
2 Replies

Related Topics

Replies
wrote...
Valued Member
Educator
10 years ago
2. What is the frequency of a 13.0 eV photon?

Use: E=hF

Where H is Planck's constant, 6.63x10^-34

1eV = 1.602E-19 J

Therefore, change 13.0 eV into Joules, then use the formula.

3. What is the wavelength of a 4.30 x 10^-19 J photon?

Use the formula: c=fλ

Rearrange: c / f = λ, where c = 3 × 10^8

1. Describe the pattern of intensity vs wavelength observed in blackbody experiments, and explain why these observations were in conflict with the predictions of classical physics. (3 marks)

"Blackbody radiation" or "cavity radiation" refers to an object or system which absorbs all radiation incident upon it and re-radiates energy which is characteristic of this radiating system only, not dependent upon the type of radiation which is incident upon it. The radiated energy can be considered to be produced by standing wave or resonant modes of the cavity which is radiating.



The amount of radiation emitted in a given frequency range should be proportional to the number of modes in that range. The best of classical physics suggested that all modes had an equal chance of being produced, and that the number of modes went up proportional to the square of the frequency.



But the predicted continual increase in radiated energy with frequency (dubbed the "ultraviolet catastrophe") did not happen. Nature knew better.
princess001 Author
wrote...
10 years ago
Thank you Slight Smile
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  932 People Browsing
Related Images
  
 222
  
 26
  
 173
Your Opinion