Wavelength◦The shortest distance between equivalent points on a continuous wave; either crest to crest or trough to trough

◦Measured in m

Frequency◦the number of waves that pass a given point per second; one hertz (Hz) equals one wave per second

Amplitude◦The wave's height from the origin to crest or origin to trough

◦Measured in m

As shown in the formula, if wavelength increases, frequency decreases. As wavelength decreases, frequency increases.

speed = λ υ

c = speed of light = 3.00 x 108 m/s

If a gamma ray traveling at the speed of light has a frequency of 2.88 x 1021Hz, what is its wavelength?

speed = λ υ 3.00 x 108 m/s = λ (2.88 x 1021 Hz)

Answer: λ = 1.04 x 10-13 m

Energy will increase as frequency increases

E = h υ◦h is a constant = 6.626 x 10-34 Js

A photon has an energy of 2.93 x 10 -25J. What is its frequency?

E = h υ 2.93 x 10-25 J = (6.626x10-34 Js) υ

Answer: υ = 4.42 x 105 Hz or 442,000 Hz

What is the energy of an ultraviolet photon that has a wavelength of 1.18 x 10-8m?◦ E = h υ

But wait? Do we have frequency? No? So…Find it!

◦ Speed = c = λ υ 3.00 x 108m/s = (1.18 x 10-8m) υ υ = 2.54 x 1016

◦ Now solve for the energy E = (6.626 x 10-34 Js) (2.54 x 1016) E = 1.68 x 10-17 J