The History of the Electron

When we last left the atom, this is how it looked

But first, we have to talk about what a wave is.

What makes up a wave?Wavelength (λ) – the distance form one

point on a wave to the same point on the next wave.

Frequency – waves that pass a point per second

Amplitude – how far a wave rises or falls

Wavelength and Frequency

Waves and Energy

The higher the frequency, the higher the energy

The longer the wavelength, the lower the energy

Electromagnetic Spectrum

What is an electromagnetic spectrum? All of the frequencies or wavelengths of

electromagnetic radiation.

Spectrum from shortest wavelength to the longest

cosmic gamma X-rays ultraviolet (UV) visible infrared (IR) microwave radar TV Radio

A nicer Picture of the Electromagnetic Spectrum

ROY G BIV backwards

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Remember the three L’s are on this side (Low energy, Low frequency, long wavelength)

Let’s Practice1) What has the longer wavelength: X-rays verses visible

2) What has the longer wavelength: gamma verses cosmic

3) What has the higher energy: infrared verses radio

4) What has the higher energy: microwave verses infrared

5) What has the highest frequency: gamma verses radio

6) What has the highest frequency: TV verses UV

See if you can find the humor in this:

Now, how do waves relate to the atom?

That brings us to Quantum Mechanics and a few more

scientists

Line Spectra of Excited Atoms

Excited atoms emit light of only certain wavelengths The wavelengths of emitted light depend on the

element.