[NinaNicole]

I do virtual school online and today my chemistry teacher gave us some classwork on calculating the frequency of radiation and I am so confused  Could anyone help me with this problem:
  Electromagnetic radiation at the blue end of the visible spectrum has a wavelength of 400 nm. Calculate the frequency of the radiation.

[P]

There is an equation which relates frequency to wavelength directly. 

[ARGOS++]

Dear NinaNicole,

Could it be possible that you don’t remember that you asked this question just two days agao?
Or was my answer not of any help to you?

Do you know what the Definition of “Wavelength” is?
And do you know how far the light travels in/during 1.00 sec?

In this case I think it is quite easy, also for you, to calculate the corresponding frequency of light with a wavelength of 400 nm (Nano-Meter = 10^-9 m).

So let’s do for this time the calculation together:
As “Frequency” is defined as the number of “Events”/Waves per seconds it follows:
     Frequency [sec^-1] = “Way of Light per sec.” / Wavelength = 3.0 * 10⁸ m/sec / λ   
       --  with λ = 400 nm.

Do you think you can do now this simple Division and tell me your result?
Instead You may control your result on the Diagram under the Question:

”Why  Einstein meets Beer-Lambert?”

on the “Spectroscopy FAQ / Beer-Lambert Bouguer Law FAQ” Page.

Good Luck!
                    ARGOS⁺⁺