Unit+One+Notes


 * __[
 * SCIENCE.bmp]][[file:SCIENCE.bmp]]History of the Atom__ **

4 elemenets= fire, water, air, earth summarized results of his experiments and those of others *Dalton's Atomic Theory 1.) All matter is made of tiny indivisible particles called atoms 2.) Atoms of the same element are identical, those of diffrent elements are diffents 3.)Atoms of diffrent combine in whole number ratios to form ccompounds 4.) Chemical reactions involve the rearrangement of atoms. No new atoms are created or destroyed
 * Orginal idea Ancient Greece (400 B.C)
 * Democritus and Leucippus-Greek philosphers
 * Aristole-famous philospher
 * *John Dalton-Teacher ( late 1700) **

__Parts of the Atom__ made a piece of equipment called a carthode ray tube. It is a vacuum tube which means all the air has been pumped out
 * J.J. Thompson-English Physicist (1897)




 * Proton- postively charged pieces that are 1840 times heavier than the electron- by E. Goldstein
 * Neutron- no charge but the same mass as a proton- by J. Chadwick


 * __Rutherfords Model of the Atom__ **




 * __Electromagnetic Radiation__ **


 * microwave O
 * infra red R
 * ultra violet
 * radio waves Y
 * x-rays I
 * visible light
 * gamma rays



__**Wavelength**__

Wavelength is large-energy is small Wavelength is small-energy is large

Frequency --> __how many times__ a period of time



Spectroscopes: instruments used to measure the behaviour of radiation

**__Bohr Model of Atom__**



Ground State Electrons: electrons in the lowest energy level Drawback of Rutherford Model of Atoms

1) The atom is not stable due to continuous emission of radiation(EMR) 2) Cannot explain the line spectra of Hydrogen like atoms

Every orbit(shell or energy level) has a fixed value for its energy (It will not change).
 * Quantised:** Fixed Energy

Energy will be absorbed or emitted in __discrete__ quantities.