First day of Atomic Structure and Radioactivity

First, we learned about Dalton's Atomic Theory. He made some great points like, that all elements are composed of atoms and all atoms of an element are identical. Also in his theory he stated that atoms are indivisible and aren't created or destroyed in a chemical reaction, but the most important thing was that Protons=Identity. Next, we learned about the Law of Constant Composition and how a given compound always contains the same proportion by mass of the elements of which it is composed. We then had to calculate the percent composition of each component in a sodium oxide (for example). Na2O was split up and then we multiplied their charges by their atomic number, so 2 • 22.99 for sodium and 1 • 16 for oxygen. Sodium came out to a total of 45.98 which was added to Oxygens total of 16 to get 61.98 g/mL. Finally for the percentage, sodiums total of 45.98 was divided by the overall total of 61.98 then multiplied by 100 to get a final result of 74.19%. Oxygen came out to 25.81%. Now we looked at JJ Thomson, and how he discovered the first subatomic particle the electron. He used a cathode ray tube to show the atoms of any element emit particles with a negative charge. Rutherford, a student of Thomson, discovered the nucleus and the proton. Lastly, we looked at the current atomic model and how it resembled a cotton ball with fluffy edges and that a mathematical equation is used in it.


Dalton, Rutherford and Thomson Help