1. Use your Foldable Notes and book (pp
Use your Foldable Notes and book (pp ) to answer the questions on the last page of your Foldable.
(5 minutes to work on your own, then 2 minutes table talk)

2. Rutherford figured out the DIAMETER of the nucleus.

3. Rutherford figured out the DIAMETER of the nucleus.
How could he do this???
He couldn’t see the gold nuclei??????

4. Rutherford figured out the DIAMETER of the nucleus.
How could he do this???
He couldn’t see the gold nuclei??????
TODAY YOU’RE GOING TO FIGURE OUT HOW!

5. Rutherford figured out the diameter of the nucleus.
How could he do this???
He couldn’t see the gold nuclei??????
TODAY YOUR GOING TO FIGURE OUT HOW!
We will use MARBLES to represent the GOLD NUCLEI
and the ALPHA PARTICLES that Rutherford shot.

6. HOW DO YOU CALCULATE DIAMETER?
MEASURE IT!!!
OR IS THERE ANOTHER WAY???

7. OBJECTIVE: Show that you can get similar diameters of a marble (nucleus) by measuring it directly or by throwing marbles at it and doing a little math. This is very similar to how Rutherford figured out the diameter of a nucleus. He couldn’t measure it directly but he could throw things and do a little math.

8. PRE-LAB INFO
In 1909 Ernest Rutherford was testing the assumption of his former teacher J.J. Thompson that atoms were made of a positively charged mushy body with negatively charged electrons floating around in the mush. In Rutherford’s famous test he shot tiny particles—even smaller than atoms—at a super thin sheet of gold foil. From this experiment, he was able to determine that all of the positive charge was in a very small nucleus at the center of the atom.
Today you will be using marbles to represent both the gold nucleus, and the even tinier particles, called alpha particles, that Rutherford shot at the gold foil. Even though our experiment is a very simplified version of what Rutherford did, it will still show you how he was able to use the number of collisions between the nuclei and the alpha particles to determine the positively charged nucleus.

9. LAB SET-UP INSTRUCTIONS
Get a set of 5 marbles plus a ‘shooter’ marble’ from your supply station.
Place 2 stacks of science books (2 books each) 30 cm apart and against the back of the lab counter.
Place all but one of your marbles (the last one will be your “alpha particle”) in the center of the books along a double-sided tape strip. Make sure that:
There is space between any two marbles for the alpha particle to pass between them (try to space them evenly).
No marble may hide behind any other marble so the alpha particle can’t hit it.
Make sure that the marbles follow rules A and B every time you shoot!

10. DIAGRAM OF SET-UP
Number of trials (T)
Number of hits (H)

11. HOW TO ROLL MARBLES
Roll the shooter or “alpha particle” down the track at the marbles.
Roll it from a random starting point, you may even want to close your eyes, but definitely don’t aim anywhere!
Roll the shooter straight down the track perpendicular to the backstop, not at an angle.
Shoot the alpha particle at the gold foil at least 100 times. Keep a running total (use small tally marks) of the number of trials and the number of hits in the first table.
If the alpha particle bounces off of the backstop and hits a nucleus do not count that as a hit.
If the alpha particle collides with more than one nucleus, just count it as one collision

13. Actual Diameter