Calculate the wavelength (in cm) of light with frequency of 4.85 x 10^15 sec^-1

1. Calculate the wavelength (in cm) of light with frequency of 4.85 x 10^15 sec^-1.

2. Calculate the wavelength of the light in question 3 in units of nm.

3. Calculate the energy associated with the light in question 3 in units of joule/atom.

I dont know if I use the plank constant to solve question one or not..
PLEASE HELP!!

1. To calculate the wavelength use the following equation... (wavelength)*(frequency) = c(speed of light)
(4.85 x 10^15 sec^-1)(wavelength) = 3.0 x 10^8 m/s.
wavelength = 6.19 x 10^-8 m
when you solve this equation you will be left with an answer in units of meters which you must then convert to cm.
(6.19 x 10^-8 m)*(100 cm/1 m) = 6.19 x 10^-6 cm

2. To convert to nm...
(6.19 x 10^-8 m)*(10^9 nm/1 m) = 61.9 nm

3. For this one you use Planck's constant. E = h(Planck's constant)*(frequency)
E = (6.626 x 10^-34 Jxs)(4.85 x 10^15 sec-1) = 3.21 x 10-18 J...this is the value for one photon (the question should probably read "per photon" not "per atom").

Hope that helped!