Understanding Photon Energy: Help Needed for Chemistry Student

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SUMMARY

The energy of a photon is defined by the equation E=hf, where h represents Planck's constant and f denotes frequency. In the context of the discussion, angular frequency (ω) is introduced, which relates to frequency by the equation ω=2πf. The derivation presented by the lecturer utilizes the relationship between angular frequency and wavenumber, leading to the equation E=hω. Understanding these relationships is crucial for chemistry students studying photon energy and its derivations.

PREREQUISITES
  • Understanding of Planck's constant (h) and its role in photon energy calculations.
  • Familiarity with the concepts of frequency (f) and angular frequency (ω).
  • Knowledge of the relationship between wavelength (λ), frequency (v), and the speed of light (c).
  • Basic understanding of wavenumber and its application in spectroscopy.
NEXT STEPS
  • Research the derivation of E=hf and its implications in quantum mechanics.
  • Learn about the relationship between angular frequency (ω) and frequency (f) in detail.
  • Explore the concept of wavenumber and its significance in molecular spectroscopy.
  • Study the applications of photon energy in various fields of chemistry and physics.
USEFUL FOR

Chemistry students, physics students, educators, and anyone interested in the principles of photon energy and its mathematical derivations.

Randomchemstudent
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Homework Statement
w/v=c,w=vc giving E=hcv
Relevant Equations
E=hw, lamda*w=c, wavenumber (v) = 1/lamda
So I'm a chemistry student here in the UK - and I'm feeling a bit like a fish out of water on a physics forum but... I'm having trouble with a derivation that seems simple but i can't for some reason seem to understand.

I know that the energy of a photon is given by E=hc and that c=lambda*v giving E=hc/lamda. But my lecturer has used w(omega) in his derivation and i don't understand what it means and why he's used it to derive the energy in this way.

Any help would be much appreciated!
 
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##\omega## is angular frequency. It differs from frequency by a factor of ##2\pi##.
 
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Spectroscopists often use ω for frequency, or for wavenumber. They (we) often loosely talk about wavenumber as frequency, e.g. "a frequency of 1730 cm-1". For example, on the NIST website, molecular vibrational frequencies in cm-1 are given the symbol ω. So you have to be a bit careful.
 
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Randomchemstudent said:
Problem Statement: w/v=c,w=vc giving E=hcv
Relevant Equations: E=hw, lamda*w=c, wavenumber (v) = 1/lamda

I know that the energy of a photon is given by E=hc
No. The energy of a photon is ##hf##, which is often written as ##h \nu##, where ##f## or ##\nu## is the frequency. You seem to have your notation mixed up.
 

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