2.  480 B.C. a  Greek philosopher  Theorized everything was made out of tiny particles – atoms  Believed that atoms were hard, solid spheres that could not be destroyed  Idea was controversial - had no evidence - no one believed him.

3.  “ The good things of life are produced by learning with hard work; the bad are reaped of their own accord, without hard work."  "Fame and wealth without intelligence are dangerous possessions."

4.  English school teacher  Formed his own atomic theory.  Elements made of tiny particles -atoms.  Atoms cannot be created or divided into smaller particles.  Atoms of a an element are different from those of any other element.

5.  Had evidence to support his idea - Democritus did not.  Viewed the atom as a hard, solid spheres - could not be broken down.  This theory was disproved by the discovery of electrons

6.  Discovered electron by using the cathode ray tube.  Cathode rays were stream of (-) charged particles.

7.  Model had (+) and (-) charges scattered throughout the atom.  Known as chocolate chip cookie model.  This model was disproven by discovery of the nucleus. Plum Pudding model

8.  Discovered nucleus by the Gold Foil Experiment.  Angles of deflection that alpha particles (+) made proved evidence of a nucleus.

9.  Model defines location and charge of nucleus – doesn’t clearly define location of the electrons.  This model is IMPROVED by the Bohr model.

10.  Model depicts atom as small, (+) charged nucleus surrounded by electrons in orbit.  Similar to the solar system, but with forces providing attraction, rather than gravity.

12.  This model states that an electrons occupy specific positions around the nucleus.  He stated that the electrons are confined to these orbits.  They can “jump” to another orbit only if some form of energy is given to that electron

13.  Bohr’s model was found to be slightly inaccurate.  The idea of an electron actually flying around in little circles turned out to have lots of problems  Electrons have both particle and wave properties.

14.  Einstein theorized that light and matter exhibit properties of both waves and of particles.  This theory helps explain the idea that electrons have characteristics of waves and particles.  In order to better understand the atomic structure, it is helpful to understand waves and the nature of light  All waves can be described by several characteristics.

15.  Some characteristics of waves are wavelength, frequency, amplitude and speed.  Wavelength (λ) is the shortest distance between equivalent points on a continuous wave.  Amplitude is the height of the wave from the origin to the crest or the origin to the trough.

16.  Frequency (ν) is the number of waves that pass a given point per second. It is measured in hertz (Hz)  Frequency is expressed as “waves per second,” (1/s) or (s -1 )  652 Hz = 652 waves/second = 652 s -1

17.  Frequency and wavelength are inversely related  As the wavelength increases, frequency decreases  Frequency is an indication of energy.  Which wave has the greatest wavelength?  The greatest frequency? 3 2

18.  All electromagnetic waves travel at the same speed of 3.00 x 10 8 m/s  The speed of light (c) is the product of its wavelength (λ) and frequency (ν). c = λ ν  Because all light moves at the same speed, it is possible to identify the wavelength or frequency of any wave.

19.  What is the wavelength of a wave with a frequency of 5.00 x 10 12 Hz ? c = λ ν c = 3.00 x 10 8 m/s ν = 5.00 x 10 12 Hz 3.00 x 10 8 m/s = ( λ ) (5.00 x 10 12 s -1 ) λ = 3.00 x 10 8 5.00 x 10 12 λ = 6.00 x 10 -5 m

20.  What is the frequency of a wave having a wavelength of 3.33 x 10 -8 m?  What is the speed of a wave with a frequency of 1.33 x 10 17 Hz and a wavelength of 2.25 x 10 9 m?  What is the wavelength of a wave having a frequency of 7.6 x 10 6 Hz? 9.01 x 10 15 Hz 3.00 x 10 8 m/s 39.5 m

21.  Light is a type of electromagnetic radiation.  Electromagnetic radiation is a form of energy that exhibits wavelike behavior at it travels through space.  Different types of electromagnetic radiation are distinguished by their wavelengths  Visible light from the sun, microwaves that cook our food, X rays that doctors use, and waves that carry radio and T.V. programs are all forms of electromagnetic radiation.

22.  We are familiar with all the colors of visible light from our everyday experiences.  If you have ever seen a rainbow, you have seen all the visible colors at once.  The various colors that we see correspond to specific wavelength and frequency  White light, a form of visible light, contains a continuous range of wavelengths and frequencies.

23.  When sun light, one example of white light, passes through a prism it is separated into a continuous spectrum of colors.  The spectrum is called continuous because all portions of light correspond to a unique wavelength and frequency.

24. What color has the greatest wavelength? What color has the greatest energy?

25.  Visible light is one part of the electromagnetic spectrum.  EM spectrum encompasses all forms of electromagnetic radiation ordered by their wavelength and frequencies.  EM spectrum contains radio and TV waves, Microwaves, infrared rays, ultraviolet rays, X rays, and gamma rays.

27.  Which type of EM radiation are the highest in energy?  Which type has the highest wavelength?  Which has a higher frequency X rays or Infrared rays?

28.  Pg. 25 in your study guide  Pg. 126 in your book Section 5.1 Assessment #12