Elementary Particle Activity

This is a measurement and graphing activity that uses the elementary particle theme as its hook.

Elementary Particle Activity

There is no student handout for this activity.

Elementary Particle Activity – Teacher’s Notes

1. Prior to this activity, the following needs to be created and/or collected for a class of 24 students:

• Make the samples for the class

• 20 envelopes with 15 notecards in each
• 60 envelopes with 12 notecards in each
• 80 envelopes with 9 notecards in each
• 60 envelopes with 6 notecards in each
• 20 envelopes with 3 notecards in each

• Gather one of each of the following the mass measuring equipment

• expensive electric balance (resolution ±0.001 grams)
• less expensive electric balance (resolution ±0.01 grams)
• triple beam balance (resolution ±0. 1 grams)
• double pan balance with masses from 1 to 50 grams (resolution ±0. 5 grams)
• basic kitchen scale (resolution ±0. 5 ounces – approx ±14 grams)
• basic bathroom scale (resolution ±0. 5 pounds – approx ±230 grams)

2. When students arrive, they are each given ten envelopes with notecards inside (these envelopes should be “shuffled” prior to handing them out so that there is a high probability that the students will receive a variety of notecard sets).

3. The students then move to their lab tables (each lab group has 4 members for a total of 40 envelopes). A different scale is placed at each table.

4. Students are asked to first group the envelopes into different logical groupings (with regards to their respective masses). After the groups have been defined, the students need to determine what pattern is present among the different groups (i.e. what distinguishes one set of envelopes from the other).

5. As students work through this lab, it will become clear that the ones using the equipment with improved resolution will have an easier time and will get more precise data. Nevertheless, all groups should analyze their data to determine what the mass of the “card” (actually cluster of three cards) and the mass of the envelope are. Use of a spreadsheet for data analysis is encouraged.

6. After all student groups have collected data and defined the pattern of the envelopes with cards, each group shares with the others their discoveries. As the precision of the equipment used improves, the groupings should be better defined and the mass estimations should be improved.

7. The expected distribution and masses are shared with the students. A discussion of whether or not the number is within the range of acceptable values given the equipment used follows.

8. Draw connections of this activity with the pursuit of the elementary particles. As the equipment has improved, greater clues leading to the properties of elementary particles have been revealed – from the discovery of the atom to the variation of atoms to the electron, proton, and neutron to quarks… and yet, open one envelope, there is still much to be discovered (reveal that there are cards in sets of 3).

9. Discuss the different ways that the mass of the card(s) and envelope were determined. Using data from one of the electronic balances, step the students through the following steps:

1. Input the data into a list within the spreadsheet.
2. Sort the mass data to determine the different groupings of envelopes.
3. Calculate the average mass of each grouping.
4. Plot the average masses (plot 1,2,3,etc. on the x-axis and the mass from smallest to largest) on the y-axis.
5. Draw a best-fit line between the points.
6. The slope of the line gives the mass increment (essentially the mass per unit) and the y-intercept is the mass of the envelope