Name: ______Hour: ______

Atomic Timeline Project Chemistry A

Purpose: To help you piece together the story of what we know about the "atom", you will be creating a timeline depicting the development of the scientific model of the atom. Your assignment is to research the major contributors and significant discoveries that have impacted the atomic model and, from this material, develop a timeline.

Requirements: Your timeline MUST: 1. Match each of the 11 scientists and/or philosophers located below to with the information describing their work AND with the picture best represents their work. 2. Be in chronological order with the dates clearly shown. 3. Be neat and legible. 4. Be electronic- Microsoft Word, Powerpoint etc.

Deadlines and Guidelines: • Your timeline must be submitted by email ([email protected]) OR in my electronic teacher dropbox on the shared drive and is due on ______by 7:45 am. The subject of the email should be your LAST NAME, FIRST NAME • You are welcome to work (but NOT copy) together in gathering your information, but your timelines are to be completed independently of one another!

Extra Credit: • Extra credit may be given for the inclusion of other atomic scientists and/or philosophers as well as for creativity. Additional scientists that may be included are Wilhelm Roentgen (1895), Henri Becquerel (1896) and Marie & Pierre Curie (1898) All required information for the original group of atomic scientists and/or philosophers should be included.

Recommended Sources: Your textbook is probably the best source of information for this project. Often the descriptions are easier to understand that what you might find on a website. Also, dates may vary on different websites.

If you choose to use a website, I would find one that is not WAAY more complicated than you need. Try searching “atomic timeline” from a search engine like Google. Part 1: Scientists/Philosophers with Dates

Henry Moseley (1914) John Dalton (1803)

Dimitri Mendeleev (1869) JJ Thomson (1898)

Robert Millikan (1909) Democritus (460-370 BC)

James Chadwick (1932) Niels Bohr (1922)

Ernest Rutherford (1911) Erwin Schroedinger (1926)

Werner Heisenberg (1927)

Part 2: Descriptions of Contributions

Improved upon the Bohr Diagram of the atom with his Electron Cloud Model which stated that electrons are found in a more general “cloud” like area around the nucleus rather than in tight rings.

Identified the neutron, the final subatomic particle. He concluded that the nucleus is made of both protons and neutrons.

Developed modern atomic theory: matter is composed of atoms, atoms are identical in size, mass etc, atoms cannot be created, divided or destroyed, atoms combine into compounds and in chemical reactions atoms are separated, combined or rearranged.

Proposed the nuclear atomic model with a centrally located, positively charged nucleus based on the result of his Gold Foil Experiment.

Discovered that atoms of each element contain a unique number of protons, referred to as the element’s atomic number. Reorganized the periodic table to create what we use today.

First person to propose that matter was not infinitely divisible. First person to use the latin term “atomos”, which means “atom”. Developed the Uncertainty Principle, which states that the exact position or location of an electron in an atom cannot be predicted.

Identified the electron (first subatomic particle) using cathode ray tubes. Proposed the plum pudding (chocolate chip cookie) model of the atom.

Determined the charge and mass of an electron using the Oil Drop Experiment.

Suggested that electrons move around the nucleus in very specific shells or rings which relate to the energy level of the electron. Created a diagram named for him that we still use today.

Organized the elements into the first periodic table, which was based on the mass of each element. This is not the exact same table that we use today.

Part 3: Visual Representations of Contributions ------

Name: ______Hour: ______

Atomic Timeline Grading Rubric ** Cut this half of the paper off and attach to your timeline when you turn it in** r s r v n n n y k g d u a r e o o e h c r e i l t t s g o k e o e i l i l e w n f l b B r a m i s l e r d i n c o o d d D a e e o h o n M h h s M r i m e T t C h e e u M c H D R S

Points:

Date in Order /2

Correct /11 Description

Correct /11 Diagram

Neat/Legible /6

Extra Credit

Total: /30