1. The problem statement, all variables and given/known data What is the period of a monochromatic light with a wavelength of 660nm? f=660nm 2. Relevant equations T= 1/f (I think?) 3. The attempt at a solution T = 1/660nm The period of this monochromatic light is 0.00152 waves/nm. Firstly, I don't know for sure that the variable T is equal to period, as this is review of last years stuff i've forgotten. Also, just to ask a quick question in this thread for my next question so I don't have to post it here, in the formula v = f& (the & is actually a weird greek symbol), what does the & stand for?