Group3

__by: Hannah__ __Grade 9 Science__

John Dalton had a gift of figuring out patterns which helped him to have the idea of the basic part of matter. To figure out his theory of the atom, he did experiments on mixtures of gases to figure out what effects properties of the individual gases, as a whole. It was in the early 1800s that John Dalton, who studied weather and discoverer of color blindness also came up with his Atomic Theory.

__The Theory: __ -Dalton’s Theory is that all matter is made up of atoms -atoms are invisible and indestructible -all atoms that have the same element are identically in mass and properties -chemical reactions take place when atoms are rearranged and moved around -elements have different types of matter -he also thought if you combined hydrogen and oxygen you could make H2O(water) -compounds are made by a combination of 2 or more different kinds of atoms -the atoms of different elements could be told by the weight of atoms -all atoms are like small spheres but could have different particles

__Strengths and Weaknesses of Dalton’s Theory__: -if you combined hydrogen and oxygen you could make H2O(water). -if two elements are combined, it is in a fixed ratio. || <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">- all atoms are unbreakable and invisible. In recent studies, under very powerful microscopes, atoms can be broken <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">-didn't know about the nucleus protons or electrons ||
 * <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Strengths of the model || <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Weaknesses of the model ||
 * <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">-all matter is made up of atoms

<span style="background-color: transparent; color: #000000; font-family: Trebuchet MS; font-size: 14px; text-decoration: none; vertical-align: baseline;">__The Process of How Dalton Developed the Model__: <span style="background-color: transparent; color: #000000; font-family: Trebuchet MS; font-size: 14px; text-decoration: none; vertical-align: baseline;">In the 1780's, Lavoisier created careful quantitative measurements which allowed the compounds t be measured with accuracy. This helped Dalton in his studies. In 1803 Dalton discovered that oxygen and carbon can be combined to make two compounds. He later on developed the Law of Simple Multiple Proportions. This law of proportions was also studied by a Swedish chemist Berzelius. Dalton explained that elements would combine with another element in fixed ratios.

__<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Dalton's representation of carbon :__



<span style="background-color: transparent; color: #000000; font-family: Trebuchet MS; font-size: 14px; text-decoration: none; vertical-align: baseline;">__Illustration of Dalton's Theory__:



<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">References:

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Dalton's Atomic Theory. (n.d.). Clackamas Community College Distance Learning. Retrieved September 27, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://dl.clackamas.edu/ch104-04/dalton%27s.htML__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Dalton's atomic theory. (n.d.). Indiana University Northwest. Retrieved September 14, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.iun.edu/~cpanhd/C101webnotes__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Dalton's Model of the Atom. (n.d.). Mr. Kent's Chemistry Regents Help and AP Chemistry Exam Review Pages. Retrieved September 22, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.kentchemistry.com/links__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Dalton Atomic Theory. (n.d.). Royal Society of Chemistry, the largest organisation in Europe for advancing the chemical sciences. Retrieved eptember 26, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.rsc.org/chemsoc/timeline__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Early Development of Atomic Theory. (n.d.). Chemistry Land Intro. Retrieved September 27, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.chemistryland.com/CHM130S/05-EarlyAtom/EarlyAtom.html__]

Thomson Atomic Model

 * By: Jane**

- In 1897 J.J Thomson discovered electrons of an atom. - He believed that the protons and neutrons were inside the atom. - He thought that the negative electrons, as he called them, were inside the atom in a homogeneous jelly like substance. - But huge positive charges inside the atom cancel that of the negative electrons. - Later, the negative charged particles were called electrons. - Later, the positive charged particles were called protons. - In 1904 J.J Thomson suggested that all atoms are sphere shapes of positive matter. - With Thomson's discoveries it helped other scientists such as **Earnest Rutherford**, one of Thomson's student, move forward in their own discoveries.

Experiment: With the help from **Francis Aston** Thomson's assistant, Thomson generated an electric current in a glass tube called cathode ray tubes. He put atoms from all elements through the cathode ray tube and it produced streams of negative charged particles. He found this out because in the cathode ray tube there was a magnet and when he put the atoms through the cathode ray tube they bent towards the magnet. Through this experiment he found that all atoms have an electric charge (electron). After he realized that there was negative charges he tried the same experiment but looking for positive charges. The positive charges are now called protons.

A Thomson Atomic Model:
 * Strengths: || Weaknesses: ||
 * - He discovered electrons || - Thought that the electrons were inside the nucleus. ||
 * - His discoveries lead to further discoveries in the future. || - Didn’t know electrons circled around the nucleus. ||
 * - Discovered the idea of positive and negative changes. || - Thought that an atom was one particle. ||



Used this website for info and image- using. (n.d.). Thomson Model (English). Retrieved September 22, 2011, from [|http://www.kutl.kyushu-u.ac.jp/seminar/MicroWorld1_E/Part]

- [|using. (n.d.). Thomson Model (English). Retrieved September 22, 2011, from] []

- Phillipchuk, K., Kvamme, B., Hounjet, C., View, T., Mohr, P., Lacy, D., et al. (2011). //Saskatchewan science 9//. Columbus:

__**Ernest Rutherford**__
**By:Marissa**

Ernest Rutherford went to the University of New Zealand and eventually to Manchester University were he with the help of his grad students, Hans Greiger and later on James Chadwick developed the new model of the atom.
 * J.J Thomson thought that the protons and electrons were both in the nucleus
 * He said that if the protons and electrons were spread throughout the atom like Thomson said then the mass of the atom would be even
 * Rutherfords thought most of the mass was in the nucleus and the electrons orbitting around were mostly empty space
 * Rutherford decided to test Thomson's theory so he made his gold foil experiment
 * He surrounded a piece of thin gold foil with a zinc sulphide sheet too detect it
 * because the mass of the atom would be evenly spread if Rutherford shot high velocity alpha particles at the foil there would not be much to deflect the particles
 * most of the particles went through but about 1 in 10 000 bounded directly backwards
 * he then came to the conclusion that a lot of the atom was empty space, other than the nucleus and that the nucleus was positively charged but the electrons were negative
 * Strengths of the Model || Weakness of the Model ||
 * * first model of the atom that had the electrons on the outside
 * first model of the atom that had a nucleus
 * explained that most of the atom was empty space || * thought the atom was one particle
 * didn’t realize there were neutrons in the nucleus until 1932 with James Chadwick
 * Doesn’t say much about the orbit of the electrons ||

This is his experiment.



This is the model of the atom.

__<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Refernce List __

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Atomic Theory. (n.d.). Welcome to clickandlearn. Retrieved September 26, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.clickandlearn.org/gr9_sci/atoms/modelsoftheatom.html__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Google Images. (n.d.). Google. Retrieved September 26, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.google.ca/imgres?q=rutherford+atomic+model+carbon&hl=en&safe=active&gbv=2&tbm=isch&tbnid=kWEoXQCK_o9GOM:&imgrefurl=http://www.dipity.com/jtwill10/personal/&docid=_uCAVrnbLhHofM&w=640&h=451&ei=3JiATrqGF-Hx0gGj6KjmDw&zoom=1&iact=hc&vpx=918&vpy=124&dur=1564&hovh=188&hovw=268&tx=161&ty=121&page=2&tbnh=118&tbnw=168&start=20&ndsp=21&ved=1t:429,r:19,s:20&biw=1366&bih=648__]

Phillipchuk, K., Kvamme, B., Hounjet, C., View, T., Mohr, P., Lacy, D., et al. (2011). //Saskatchewan science 9//. Columbus: Pearson.

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">Rutherford - Atomic Theory. (n.d.). Royal Society of Chemistry, the largest organisation in Europe for advancing the chemical sciences. Retrieved September 22, 2011, from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.rsc.org/chemsoc/timeline/pages/1911.html__]

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">The, 1. t. (n.d.). Rutherford model of the atom. Indiana University Northwest. Retrieved September 14, 2011,

<span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 14px; text-decoration: none; vertical-align: baseline;">from <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 14px; vertical-align: baseline;">[|__http://www.iun.edu/~cpanhd/C101webnotes/modern-atomic-theory/rutherford-model.html__]

John Dalton(early 1800)
====Dalton studied weather and discoverer of color blindness also came up with his Atomic Theory. His atomic theory was that all matter is made up of small indidistuvtable indivisible parts called atoms. All atoms of one element are identical in properties and mass. With his knowlge of atoms he thought that all atoms were like small spheres but they could have different properties. Dalton also didn’t know the different parts of atoms, like protrons electrons and the nucleus. Which J.J Thomson partly discovered. ====

J.J Thomson (1897)
Thomson discovered electrons of an atom. He believed that the electrons were inside the atom instead of what we know today are orbiting around the nucleus. He thought that the negative electrons, as he called them, were inside the atom in a homogeneous jelly like substance. He found out through his experiment that huge positive charges inside the atom cancel that of the negative charges. Later, the negative charged particles were called electrons and the positive charged particles were called protons. Thomson projected rays of electrons through a glass tube with a magnet inside and discovered that the atoms bent toward the magnet. Soon after Thomson’s discovery of electrons Ernest Rutherford found out that most of the mass was made up of the nucleus.

Ernest Rutherford(1911) Rutherford discovered that most of the mass was in the nucleus and that the nucleus was positively charged. He also discovered that the negative electrons were orbiting the nucleus. Rutherford then decided that a lot of the atom was empty space except for the nucleus.He discovered this by using his gold foil experiment which I explained earlier.

Neils Bohr(1913) Bohr discovered that electrons are arranged in a specific order. The maximum number of electrons orbiting around the nucleus in the first three levels are two, eight and eight. In Bohrs experiments electrons jump and move around between energy levels around the nucleus by gaining and losing energy. Each level around the nucleus contains a specific number of electrons.

====The Bohr model failed. It failed because it only applied to one element, hydrogen. The successor model is the one we use today. The modern quantum mechanical model. In this model the electrons don't exist as tiny points inside the the atom. The electrons have specific energy levels like the Bohr model but they surround the nucleus. They call the electrons that surround the nucleus an "electron cloud" because of the shape they form.====