Maggie+Edwards

For a bonus point:
 * 1) History of the Atom (5pts)
 * Find out the important scientists who contributed to our current knowledge of the atom. Include:
 * A picture.
 * When they lived.
 * What they did.
 * Find out the important experiments that were used to make breakthrough discoveries.
 * Who perfomed these experiments?
 * Include years of each discovery/experiment so we can get an idea of how long this process has taken.
 * 1) Atomic Structure (5pts)
 * What are the different parts of the atom?
 * What are the different particles that make up the atom?
 * Where are they located?
 * What makes atoms of different elements different?
 * 1) Add an APPROPRIATE comment to someone's page through the discussion tab.

History of the Atom




 * An important scientist who contibuted to our current knowledge of the atom is John Dalton. He came up with his Atomic Theory, which he puplished in 1803. His theory stated that "all matter is made up of small indivisible particles termed atoms", "atoms of a given element possess unique characteristics and weight", and "three types of atoms exist." He lived from the year 1766 to 1844. Dalton also lived in England. (Facts taken from [] and [] )
 * Another scientist/philosopher who contributed to our current knowledge of the atom is Democritus. He lived from 460 B.C. to 370 B.C. He was one of the two founders of the ancient atomist theory. (Facts from [] and [])

There were also experiments used to help scientists discover the atom.
 * J.J. Thomson did and experiment which involved passing an electric current through gases at a low pressure. He then sealed the ends with electrodes, which were connected to a source of electricity. The result was a cathode ray or, in other words, a glowing beam. The discovery of the electron came out of this experiment which took place in 1897. (Facts from the Chemistry Book and [] )
 * Another experiment was done by E. Rutherford and H. Geiger from 1909 - 1911. The reason for doing this was that they thought that particles would be able to pass through them. Their experiment was they shot alpha particles at a thin piece of gold foil; when this happened, some passed through like they hoped, but others deflected at a slight angle, and others at a sharp angle. They concluded that there was a large concentration of positive charge within the atom. This led them to the discovery of the atom. (Facts from [] [[image:atom.jpg width="375" height="278" align="right" caption="An Atom"]])

Atomic Structure


 * The parts of an atom are the electrons, protons, and neutrons. Atoms also have a nucleus and outer shells
 * The different particles that make up an atom are electrons, protons, and neutrons. Electrons are the negatively charged particles. Protons have a positive charge and neutrons have a neutral charge.
 * Protons and neutrons are located within the nucleus. Electrons orbit around the nucleus in shells, also called energy levels.
 * Atoms of different elements are different because each element is made up of different amounts of protons, neutrons, and electrons. This is shown with different atomic mass and different atomic numbers.

Facts for this section found from []; []; []