The red light emitted by a helium-neon laser has a wavelength of 632.8 nm. What is the frequency and energy per photon of that light?
- Anonymous1 year agoFavorite Answer
Frequency = speed of light / wavelength
energy per mole = Avogadro's number * Planck's constant * speed of light / wavelength
- MyRankLv 611 months ago
Wavelength (λ) = 632.8nm
Speed of light (c) = 3 x 10⁸m/sec
Planck’s constant (h) = 6.626 x 10⁻³⁴J.sec
Frequency (f) = ?
Energy (E) = ?
We know that:-
Frequency (f) = speed of light (c) / wavelength (λ)
= 3 x 10⁸m/sec / 632.8 x 10⁹m
= 4.7 x 10⁻⁴/sec
= 4.7 x 10⁻⁴Hz
∴ frequency (f) = 4.7 x 10⁻⁴Hz
Now, Energy (E) = hf = 6.626 x 10⁻³⁴ x 4.7 x 10⁻⁴
= 31.14 x 10⁻³⁸
≈ 31 x 10⁻³⁸J
∴ Energy (E) = 31 x 10⁻³⁸J.Source(s): https://myrank.co.in/