1. Electromagnetic spectrum

2. Spectrum Very broad Wavelengths from 10-3 to 1013 nm
Only small portion is visible to humans
400nm (violet) to 700nm (red)
ROYGBIV

3. Wave Characteristics
Amplitude
Vertical distance from the centerline

4. Wave Characteristics
Wavelength (λ)
Measured from crest to crest

5. Wave Characteristics
Frequency (v)
Cycles (waves) per second

6. Wave Characteristics Speed of light in a vacuum 3.00 x 108 = c
Speed , wavelength and frequency are related
c = λv
v = frequency
λ = wavelenght

7. Wave Components Two components Electric field Magnetic field
They both have the same characteristics (wavelength, frequency, and amplitude)
Perpendicular to eachother

8. Wave Components

9. How Light Moves Double slit experiment Thomas Young Early 1800’s
When light passes through a single slit it forms a cone shape on a plane behind the slit
When light passes through two slits the light waves interfere with itself

10. Wave Components

11. Wave Components When an object is heated it gives off radiation
Over a wide range of the spectrum
Energy given off by an object at a certain temperature depends on wavelength
Some theories explained the long wave-length dependence
Other theories explained the short wave-length dependence

12. Quantum Theory Old theory was radiant energy was continuous
Based on blackbody experiments
Planck proposed the energy was actually in packages or bundles
Called these packets of the smallest quantity of energy quantum

13. Quantum Theory
The energy of a single quantum is always in whole numbers
May seem strange but many of the smallest units we are used to are in whole numbers
Soda, eggs…

14. Quantum Theory Energy of the quantum is dependent on the frequency
E = hv
E is the energy of a quantum
v is the frequency
h is Planck’s constant 6.63 x 10-34J·s

15. Two Equations c = λv E = hv c is a constant 3.00 x 108 m/s
h is a constant 6.63 x J·s

16. Electron Energy En = -2.18 x -18 J (1/n2)
As electron gets closer to nucleus
Has more energy
When n=1, at ground state
When n>1, excited

17. E = hv

18. EM Spectral Lines

19. EM Spectral lines

20. EM Spectral lines