Chemistry Ms. Ye
Name __________________________ Date ______________ Block ______
Webquest: Atomic Theories and Models Answer the following questions regarding the progression of the model of the atom. Early Ideas About Atoms: Go to http://galileo.phys.virginia.edu/classes/252/atoms.html and read the section on “Early Greek Ideas” in order to answer the following questions: 1. What was the “basic idea” about matter that Leucippus and Democritus proposed?
2. How did they use atoms to explain different physical properties?
3. How were the ideas of these two men received by Aristotle, and what was the result on the progress of atomic theory for the next 2,000 years?
John Dalton’s Atomic Theory: Go to http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html and use the information there to answer the following questions: 4. When did Dalton form his Atomic Theory (often known as the Billiard Ball or Solid Sphere Model)?
5. What are the four components of Dalton’s Atomic Theory?
J.J. Thomson: Go to http://www.chemheritage.org/classroom/chemach/atomic/thomson.html and use the information there to answer the following questions: 6. What is the year in which J.J. Thomson discovered the electron?
7. What was the name of the experiment in which Thomson discovered the electron?
8. What was the evidence for “bodies much smaller than atoms”?
9. What was the model of the atom he proposed in 1904? Sketch a picture of this model
Rutherford and Bohr Break the “Plum Pudding” Model: Go to http://www.pbs.org/wgbh/aso/databank/entries/dp13at.html. Use the information found there to answer the following questions: 10.Describe Rutherford’s Gold Foil Experiment
11.How much smaller was the nucleus, than the atom itself, according to Rutherford? Sketch a picture of Rutherford’s model of the atom
12.How did Bohr modify the plum pudding model of the atom (i.e. what was his “revolutionary idea” about electrons)?
Chadwick (and Rutherford): Go to http://www.pbs.org/wgbh/aso/databank/entries/dp32ne.html and use the information found there to answer the following questions: 13.What makes up the atomic number?
14.What makes up the atomic mass?
15.What observation led Chadwick (and Rutherford) to conclude there must be something besides just the proton in the nucleus of atoms?
16.What is the something-besides-just-the proton called?
Modern Model of the Atom: Go to http://science.jrank.org/pages/626/Atomic-Models-modern-atomic-model.html 17.In the mid 1920’s, de Broglie and Schrodinger suggested that electrons have properties of both…
18.The current model of the atom depicts electrons to be located in regions called orbitals. Briefly describe what an orbital is.
Atomic Theory Timeline Assignment Purpose: Create a visual timeline showing the evolution of our understanding of the atom. 1. Atomic timeline models must include the ideas of the following scientists: a. Democritus b. John Dalton c. JJ Thomson d. Ernest Rutherford e. Neils Bohr f. James Chadwick g. Irwin Schrödinger 2. Atomic timeline models must include the following text/information: a. Date (year) of discovery b. Name of the scientist c. Scientist’s main ideas, concept of the atom, or major contribution (paraphrased, can be in bullet form) 3. Atomic timeline models must include illustrations (hand-drawn, picture, or graphic art) of each scientist’s concept of an atom. 4. Atomic timeline models must also include an illustration (hand-drawn, picture, or graphic art) and brief summary of Rutherford’s gold foil experiment. Timeline Rubric _________: Accurate descriptions of the contributions to atomic theory by each of the scientists above (15 pts) _________: All pictures & names of the models of the atom that correspond with each scientist are included (and accurate) (7 pts) _________: Includes picture and summary of Rutherford’s gold foil experiment (3 pts) _________: Quality workmanship, neat, organized, readable (5 pts)
Structure of an Atom Go to http://phet.colorado.edu/en/simulation/build-an-atom and click on “run in html5”. Click on “Atom” and use the simulation to answer the following questions.
*Follow the instructions and write the charge of each subatomic particle in table 1 below. 1. Place one proton (red) in the atom. 2. Remove the proton. Now place one neutron (gray) in the atom. 3. Remove the neutron. Now place one electron (blue) in the atom. Table 1.
Proton
Neutron
Electron
Charge *Create the atoms on the PhET simulation based on the information given in the first column titled “Atom description;” and complete the rest of the information on table 2. Table 2.
# 1 2 3
4 5 6 7
Atom description 1 proton (no neutrons; no electrons) 2 protons (no neutrons; no electrons) 2 protons and 1 neutron (no electrons) 2 protons and 2 neutron (no electrons) 2 protons; 2 neutrons; and 1 electron 2 protons; 2 neutrons; and 2 electron 2 protons; 2 neutrons; and 3 electron
Name of element
Mass number
Charge of atom
4. For table 2, you changed the number of protons for #1 and #2. Did the element change? Did the mass or charge change?
5. For #2, #3, and #4, you kept the number of protons the same, but change the number of neutrons. Did the element change? Did the mass or charge change?
6. For #4, #5, #6, and #7, you kept the number of protons (2) and neutrons (2) the same, but changed the number of electrons. Did the element change? Did the mass or charge change?
7. Based on your observations above, complete the table below. Subatomic particle(s) (protons, neutrons, Property electrons) that determines property Identity of element (type/name of element) The Mass Overall positive or negative charge
What can you determine about the structure of an atom of a specific element based on its information on the Periodic Table? 1. The following key gives you the information a periodic table provides about an atom of a specific element
2. Create an oxygen atom with a mass of 15 and a charge of +1 on your simulation. Determine how the number of protons, neutrons, and electrons relates to the atomic number and atomic mass. a. The atomic number equal to the number of ___________________________ b. The mass number is equal to ____________________ + ____________________ c. Alter your oxygen atom so that it has a charge of 0 (neutral). For neutral atoms, the number of electrons is = # of _________________________
Atomic Structure Practice: Fill in the missing information. The first one has been done for you as an example. Assume these are all neutral atoms! Nuclear Notation
Full Notation
Lithium-7
Atomic Mass # # # Number Number Protons Neutrons Electrons 3
7
15
31
35
3
4
3
17
28
31
39
19
47
61
1
1
14
74
14
110
10
10
