1. Chemistry Unit 3 Chapter 4 and 5 – Atomic Structure

2. 5.3 Electromagnetic radiation - a series of energy waves that includes radio waves, microwaves, visible light, infrared and ultraviolet light, X-rays, and gamma rays.

3. Electromagnetic Spectrum

4. We can measure not only the length of each wave of light, but also its frequency of occurrence.

5. Parts of a wave:
Draw this!
Amplitude

6. amplitude- height of the wave from the origin to the crest wavelength -  - distance between the crests frequency -  - the number of wave cycles to pass a given point per unit of time.The units of frequency are 1/s, s-1, or Hertz (Hz)

7.  = c/ where c = speed of light c= 3
 = c/ where c = speed of light c= 3.00 x 108 m/s As  increases,  decreases.

8. Questions: Try to rearrange the light formula in at least two ways.
Complete the following by circling an answer:
As the wavelength of wave increases/decreases,
the frequency will increase/decrease.

9. Ex. A certain wavelength of yellow light has a frequency of 2
Ex. A certain wavelength of yellow light has a frequency of 2.73 x 1016s-1. Calculate its wavelength.
 = c/
= c/
= 3.00 x 108m/s
2.73 x 1016s-1
= 1.10 x 10-8 m

10. Spectrum- series of colors produced when sunlight is separated by a diffraction gradient ROY G. BIV Red: has the longest wavelength, lowest frequency  Lowest energy Violet: has the shortest wavelength, highest frequency  highest energy

13. Atomic emission spectrum A series of lines produced by passing the light emitted by an excited atom through a diffraction gradient. These spectra can be use in element identification.

15. Max Planck believed that energy was emitted or absorbed by small units called quanta. He found that the amount of energy released or absorbed was proportional to the frequency of the radiation. E = h ν E = Energy ν = frequency h = Planck’s constant: 6.63 x J∙s Einstein proposed that light could be viewed as a stream of particles called photons.

16. Einstein proposed that electromagnetic radiation can be viewed as a stream of particles called photons. His famous equation, E = mc2 helped to determine the amount of energy released as radiation from a certain mass.

17. Example: Calculate the energy of an individual photon of yellow light having a frequency of x 1016s-1.
E = h
E = (6.63 x J.s )(2.73 x 1016 s-1)
E = 1.81 x J

18. Friday homework: 1. Label the parts of the wave shown below.
2. A wave of red light has a frequency of 4.77 x 1015 s-1. What is the wavelength of this light?
3. Which energy source below would emit photons with the greatest wavelength? Which would have the highest energy particles?
a. A radio tower
b. A microwave in your kitchen
c. An X-ray machine in the dentist’s office
d. A lamp in your home