What are the frequency and energy of a photon with a wavelength of 670. nm?

Question

I just need the frequency. I keep getting it wrong and I don't know what I'm doing wrong.

Answer 1

speed of light = wavelength x frequency

Since wavelength is given in nm, we'll change it to m to be consistent with the units for the speed of light.

670 nm x 1 m / 1x10⁹ nm = 6.70x10^-7 m

3x10⁸ m/s = 6.70x10^-7 m x frequency

frequency = 3x10⁸ m/s / 6.70x10^-7 m

frequency = 4.48x10¹⁴ s^-1