Frequency question

Question

what frequency is associated with 656.28 nm?

Answer 1

For this question and for 2 similar questions you posted below, use the formula

 

f = c/λ

 

c = speed of light = 3 x 10⁸ m/s

λ = 656.28 x 10^-9 m

 

Plug in the numbers and get a frequency in Hz.  Work the other 2 problems the same way.