Unit+2--Atoms,+Ions,+and+Nomenclature

__Unit 2: 4-5__

Niels Bohr’s model is a modified version of the Rutherford model and is often referred as the Rutherford-Bohr model. Bohr noticed that all atoms are unstable in the Rutherford model because the electrons would lose energy and eventually collapse into the nucleus. Bohr modified that model to fix this problem. He stated that electrons do not lose energy as they orbit their nucleus but rather electrons lose energy as they move to a lower energy orbital also noting that light is emitted as electrons move through orbitals.
 * 4:

Particle || Charge || Mass || Position in Atom || Proton || Positive (+) || 1.67 * 10 -27 kg || Inside nucleus || Neutron || N/A || 1.67 * 10 -27 kg || Inside nucleus || Electron || Negative (-) || 9.11 * 10 -31 kg || Outside nucleus (electron cloud) ||
 * 5:

__Unit 2: 6-7__

|| 1) Dalton devised the first system of chemical symbols and arranged them into a table by weight. He also developed the theory that a chemical combination of different elements occurs by ratios by weight, giving way the laws of definite and multiple proportions. In addition, he claimed that molecules were made of atoms. 2) T here are 6.022x1023 atoms in 12 grams of Carbon, and that the usual diameter of an atom is 10-8cm. 3)Ernest Rutherford discovered that most of the atom’s mass and positive charge was concentrated in a very small fraction of its volume, at the very center. He then proposed what is now known as the Rutherford model, where the atoms was made of a nucleus of 10−15 m in diameter, surrounded by an electron cloud of approximately 10−10 m in diameter. 6. Atomic Number- the number of protons in an element Mass Number- the total number of protons & neutrons in a nucleus Average Atomic Mass- the average mass in an atom
 * **The Atomic Theory**
 * ||  || Democritus first proposed the existence of atoms. ||   || Joesph Loschmit estimated the atom's diameter. (2) ||   || J.J. Thompson discovered the electron. ||   ||
 * **5th Century BC** ||  || **1865** ||   || **1897** ||   ||   ||
 * [[image:http://www.teach-nology.com/web_tools/materials/timeline/line.gif width="640" height="30" caption="external image line.gif"]] ||
 * ||  || **1803** ||   || **1869** ||   || **1909** ||
 * || John Dalton determined elements differ by mass. (1) ||  || Dmitri Mendeleev proposed the Periodic Law. ||   || Rutherford created the 'plum pudding' atomic model. (3) ||   ||   ||

7.Isotopes are one of two atoms with the same atomic number but different mass numbers Do either of the following pairs represent isotopes of one another? i. 40K19 and 40Ar18 No ii. 90Sr38 and 94Sr38 Yes

Determine the number of protons, electrons and neutron i. 210Pb82 Protons: 82 Electrons:82 Neutrons:128 ii.34S16 Protons:16 Electrons:16 Neutrons:18

10.Nuclear fusion is the jointment of two unstable or weaker nuclei to form on strong bond,whereas nuclear fission is the displacement of an heavier nuclei into a seperate nuclei energy. 11. Molecules are the individual make up of any properties meaning that molecules makeup ions. Ions are the finish product the whole property meaning just the single property.
 * To determine the number of protons & elctrons, find the atomic number.
 * To determine the number of neutrons, subtract the mass number by the atomic number