chemistry/mathematics

Question

Determine the energy, in J, of a photon with a wavelength of 309 nm. (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)

Answer 1

Hello, Tanya,

I'm not sure what aspect of this problem you'd like help on. I'll assume you have access to the basic relationships between photon energy, wavelength and frequency. I've added some key information here:

The relationship to be used here is E=hv. Since the problem gives us wavelength, we need to convert that to frequency (v, in s-1).. Use c = λν to convert 309 nm to 9.71x10¹⁴ s^-1 (Hz). Remember that 1 nm - 1x10^-9 m. It is critical to pay attention to the units and that everything cancels to leave just the units you want.

Using E=hv, we can now find that a photon of wavelength 309 nm has an energy of 6.43x10^-19 J.

I hope this helps,

Bob