Instructors info:



GSI notes:

Week 1

S1b: take pictures of students to remember names; get into groups for check-in; one drawer per group of three at a lab bench; safety lecture; collect group contract for ICP

S1c: Icebreakers; Great chance to go around to groups and make sure that they are in their roles (speak only with reporter); facilitate discussion/summary at end; really build on scientific method. Collect ICP-S1c

Week 2

S2a: Demonstrate use of the balance

Write the two questions (1a,b,c) up on the board.

Between 1962 and 1982, pennies were 95% copper and 5% zinc (mass 3.1g). During1982, the composition was switched to 97.6% zinc, and 2.4% copper.(mass 2.5g)

Diameter: 19.mm, Thickness:1.25 mm

There are 8 groups of pennies (2 random, 1960s, 1970s, 2-1980s, 1990s, 2000s) as students get done taking data and graphing it; then begin data collection discussion.

Start with hypothesis. Take a survey.

Then goto the data collected to answer the first question. Start with the random groups and get them to show both of their graphs. Analogy to Battleship (take systematically random approach until you find a target.) Then create a new hypothesis and a new plan for “collecting data.” (What data would you want to have?) Then you can go through decades systematically by decade or zoom in on the 80s and then go through the other decades. Remember that you need to confirm that the composition didn’t change through 2006. Look at both graphs from each group if possible.

Have students collect all of the data in an Excel file (S2a_pennies) which they e-mail you. Collect all of the data and e-mail it back out. Then put them to work on the rest of the questions and problems.

Last fall, the classes did not get to do the problems. Tell the students that the are good practice problems and you may return to them later.

Collect ICP-S2a

S2b pretty much runs on its own; students should be self sufficient but worth going around and asking questions. Make sure they are taking on their group roles; discussion to wrap things up at the end. No ICP today

S2c

Foiled Again (30 minutes)

Objectives

Students will identify alternate forms of measurement for very small objects (weighing).

Students will solve problems by analyzing and using conversion factors.

Students will evaluate the soundness of their answers.

Students will be able to explain why we use the mole.

Misconceptions

Students feel they cannot measure the thickness accurately.

Student Difficulties

Students may find it hard to relate mass and moles to a form of measurement.

Relating the macroscopic measurements to microscopic measurements.

Incomprehensible size of atoms. Finding a conversion factor for atoms/cm.

|Task |

|Reason |

|Notes |

| |

|Place a large jar of candy in front of classroom and have students guess how many pieces of candy are in the jar. Winner gets the jar. |

|Grabs attention of students. |

|Only collect the guesses. |

| |

|Ask students to devise a method of determining the number of candy pieces without counting them. |

|Requires problem solving. Students should end up wanting the mass of the candy and dividing by the mass of one piece of candy. |

|After students solve the problem announce a winner. |

| |

|Ask students to measure the thickness of a square piece of aluminum foil in centimeters. |

|Students will see the need for alternate methods of measurement. |

|Instruct students that only accurate measurements will be considered. |

| |

|When students cannot determine the thickness ask them to determine the number of atoms in the aluminum foil. |

|The students will have to relate it to mass (like the candy problem) and Avogadro’s number. |

|The approximate mass is 0.045 g for a one-inch square piece of aluminum foil. |

| |

|Give students density of aluminum to determine the volume of their aluminum foil in centimeters. |

|Using conversion factors. |

|Density = 2.70 g/cm3 at 25oC |

| |

|Ask students to determine thickness in centimeters. |

|Using conversion factors. |

|  |

| |

|Ask students to determine the thickness in terms of atoms. |

|Hint: They need a conversion factor for atoms/cm. |

|Shows that atoms are very small and relates atoms to a measurement. |

|Must convert density to atoms/cm3 and then take the cube root. This is very difficult for students. |

| |

|Have students evaluate the soundness of their answers. |

|To visualize size of atom. |

|Foil should be approx. 1 x 105 atoms thick. |

| |

|Ask students to compare the candy problem with what they did with aluminum foil and to comment on the importance of the mole (put it in writing). |

|Students have to relate macroscopic candy to microscopic atoms to determine why the mole is useful. |

|Students will have to realize that counting in chemistry is done by weighing. |

| |

|Discuss the results. |

|To relate mass, moles, dimensional analysis. |

|The size of atoms and the importance of Avogadro’s number should be realized. |

| |

|Ask students to determine how much money their aluminum would be worth if each atom were a penny and how long would it take for them to spend it if they spent it at a rate of |

|$100 billion a day. |

|Concluding activity to stress the incomprehensible size of atoms. Practice with conversion factors. |

|Their answer should be of the magnitude of 105 years. |

| |

New Element (15 min)

Objectives

Students will determine the "atomic mass" of M&Ms.

Students will use Avogadro's number.

Misconceptions

Atomic mass is the mass of an atom of an element

|Task |

|Reason |

| |

|Ask students "If M&M's were to be added to the periodic chart as a new element what atomic weight would be used?" |

|To evaluate the students' knowledge of how to use Avogadro's number and understanding of what atomic mass is. |

| |

|Have students explain how they determine their answers. |

|To evaluate their method. |

| |

|Give students other questions to practice using the mole. |

|To review. |

| |

Notes: This activity will clearly show any misconception students have about the mole and atomic weight. Many students will report the mass of one M&M as the atomic weight. Asking students if one atom of hydrogen weighs more than ONE M&M can clear up some confusion. Other students may try to determine a "molecular" weight by using ingredients in an M&M, thus missing the definition of "element" altogether. Others may probe deeper and will want to know how many protons and neutrons are in an M&M. These students are trying to use the formal definition of atomic mass. Finally, some students may bring up the fact that there are many different types of M&M's (plain, peanut, peanut butter, almond, etc.). This fact can be used to discuss isotopes.

Collect ICP-S2c

Week 3

S1a Atomic Hotel (30 minutes)

Objectives

Students will be able to define Aufbau principle, Pauli Exclusion Principle, and Hund's Rule.

Students will be able to distinguish between ground and excited states.

Students will be able to determine when these quantum mechanical rules are broken or not.

Students will be able to list and describe the four quantum numbers.

Students will be able to explain the "order of evacuation" of electrons from an atom.

Misconceptions

An electron in the excited state breaks Hund's Rule.

Difficulties

Understanding why a 3d level can fall between 4s and 4p

|Task |Reason |

|Allow students to work through the provided worksheet. |To introduce a simple analogy to help students understand quantum mechanical |

| |rules. |

|Summarize all the rules and definitions covered on the |To give the rules in a chemistry setting rather than a "hotel" setting. |

|worksheet. | |

There is a PP to guide this studio. The atomic hotel is a great analogy; then you get to help make the connection to real atoms.

S3b Students should do most of this work on their own. Walk around to help groups with questions and keep them on task. At the end, hold a review/discussion. Have each of the groups tell you the general direction of one of the trends by drawing directional arrows as shown for atomic number on the first page of the studio.

Collect ICP-S3b

S3c

Collect their penny lab reports at the beginning of the studio. Mark anyone whose is late (+/- five minutes as 10% off.)

There are three things going on today

1) They create their own periodic table from “fictional” elements

2) They learn about periodic trends in LEDs

3) They tackle a periodic trend problem Doubleelectron

ICP points should be awarded for periodic table presentations; LEDs is a mini-lecture, please prepare accordingly. Double electron will throw them for a loop. Insist that they can do it and that it is a good check of their understanding of the rules associated with electrons and atoms

Week 4

S4a Lewis Structures. Students should work in groups. Again, move around to answer questions and ask questions to keep the students moving along. May want to do a discussion/wrap up at the end

For ICP today do a one-minute paper. ~ 3 minutes before the end of class ask the students to individually write on a sheet of paper what they found to be the most confusing and what questions they still have.

S4b: VSEPR This will be a challenging day for students, but they will learn a lot. Note: we don’t talk about hybridization in class.

You might do a little intro to the rules; you might not.

Have students work through 3 & 4. Assign one table to present “3” showing off their Lewis structures, models, angles, and names for geometries. Ask the students which should be the same for each of these molecules the electron pair geometry or the molecular geometry. Verify correct angle measurements. (120o and ~115o) Tell the students the actual electron pair geometry and molecular geometry names. (The book uses triangular planar and angular (as opposed to trigonal planar and bent).

Then have each of the other three tables present one of group of “4,” including their Lewis structure, model, angles, and geometry names. Students will have a very hard time coming up with the tetrahedral shape! You will probably see mostly a 2-D structure with all of the hydrogen atoms in the same plane. If no one gets a tetrahedral structure, ask them about the bond angles and if it is possible to spread the atoms out more evenly? Ask them to think 3-D and start by moving one hydrogen out of the plane. Give them a minute or two to work on their structure. Then see if any are close. Show them the shape and give them the bond angles (109.5o) for methane. Then ask them to adjust their work with this knowledge. Collect all of the answers and provide the actual geometries and angles (Tetrahedral, triangular pyramidal, angular and 109.5o, 107.5o, and 104.5o)

Once everyone is set on the “3” and “4” geometries, let them move onto the “5” and “6” geometries. Have each group present one of the 5 or 6 molecules. Collect ideas for geometries and the supply the correct geometries and angles.

5: Triangular bipyramidal (90o/120o/180o), seesaw (~ ................
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