Violet light has a wavelength of 4.10x10 to the power of - 12m what is the frequency?

Frequency of any wave = (the wave's speed) divided by (its wavelength)

Speed of light = about (3 x 10 to the 8) meters per second, in vacuum.

Frequency = (3 x 10 to the 8) / (4.1 x 10 to the - 12) = 7.317 x 10 to the 19 Hz.

That's the same as 73,170,000,000 GHz.

Note:

That's the answer for the information given in the question, but the information in

the question is incorrect by 5 orders of magnitude. The wavelength of violet light,

or anything in the visible range, is a few hundred 'nanometers' ... a few hundreds

of 10 to the - 9. So the number in the question should be 4.10 x 10 to the - 7,

not - 12, and the frequency should be 731,700 GHz.