c = speed of light 3x10⁸ m/s
l = wavelength
n = frequency
E = energy of photon
h = Planck's constant = 6.626x10^-34 J*s
c = l * n speed of light equals wavelength times frequency of that light
E = h * n energy of light waves equals Planck's constant times the frequency of the wave

                                                                                    ROYGBIV

                                                                                                                        800 nm-----400 nm

PRACTICE PROBLEMS:

1. If a wave of length 520 nm travels through space, what is its frequency? In what region of the electromagnetic spectrum does this lie?
2. If a wave has frequency of 3.4x10¹⁴Hz, what is its wavelength? In what region of the spectrum does it lie?
3. Find the energy for green light (550nm).

ANSWERS:

1. frequency=5.76x10¹⁴ Hz; approximately greenish blue

2. wavelength = 8.82x10^-7 m = 882 nm; approximately infrared region

3. frequency = 5.45x10¹⁴ Hz; so energy = 3.6x10^-19 J