A beam of light has a wavelength of 4.5 * 10^-7

meter in a vacuum. The frequency of this light is

(1) 1.5 * 10^-15 Hz (3) 1.4 * 10^2 Hz

(2) 4.5 * 10^-7 Hz (4) 6.7 * 10^14 Hz

Wavelength formula is C=λf or λ=C/f or f = C/λ, so Frequency = Velocity divided by wavelength, where C is the velocity, which is the speed of light: 3.00*108 m/sec

λ is the wavelength in meters

f is the frequency in Hertz (cycles per second)

f=3.00 * 108 msec / 4.5x 10 - 7 m=6.7x 1014 H z