ELECTRONS AND THE ELECTROMAGNETIC

SPECTRUM

Electromagnetic

Spectrum

Wave Characteristics

WAVELENGTH – the distance between two

consecutive wave peaks; symbolized by the Greek letter lambda (λ)

FREQUENCY – indicates how many wave peaks pass a certain point at a given time; symbolized by the Greek letter nu (ѵ)

EM Radiation Travels in Waves

Wave Characteristics

AMPLITUDE – height from origin to crest or origin to trough.

SPEED – ALL waves travel at a speed of 3.00 x 108 m/s

EM Radiation Travels in Waves

Wave

Characteristics

Max Planck – matter can gain or lose energy only in a small, specific amount called a quantum.

Albert Einstein - light is made up of a stream of tiny particles called photons.

A photon carries a quantum (a discreet amount) of energy.

Light has properties of both waves & particles.

C the speed of light is 3.00 x 108 m/s

λ (lambda), the wavelength is normally given in the SI units of m, cm or nm

Ѵ (nu), the frequency of a wave is measured by counting the number of waves that pass a certain point per second. The SI unit for frequency is one hertz which is written 1/s or s-1

Wave Terminology and Units

The speed of light is equal to the frequency of the wave multiplied by its wavelength.

c = λѵ We can rearrange the equation if we are trying to find wavelength or frequency.

λ= c/ѵ or ѵ= c/ λ

Putting it Together

What is the wavelength of a

microwave having a frequency of 3.44 x 109 Hz?

We are looking for wavelength so we will use λ= c/ѵ

λ= 3.00 x 108 m/s 3.44 x 109 Hz

Practice

λ= .872 X 10 -1 m or 8.72

X 10 -2 m

Answers