Lesson Idea Template
Instructional Alignment to Three Dimensions of SDSS
Student Science Performance
Grade: HS Chemistry
Title
Nuclear Marbles Lab
Topic : Rutherford's Gold Foil Experiment
Standard from South Dakota Science Standards:
HS-PS1-2 Construct and revise an explanation for the outcome of a simple chemical reaction based on the
outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of
chemical properties.
Lesson Performance Expectations:
Students use representations to reflect on phenomena and describe the structure relationships.
Students use mathematical expressions to represent phenomena to support explanations in systems that are too
small to observe directly.
Students collect data and generate evidence to answer scientific questions to describe the structure relationships.
Student Science Performance
Gathering
(Teacher Tip: Prior to beginning this activity, students should be assigned a reading on Rutherford's Gold Foil
Experiment, including basic comprehension questions). Experiment based on
http://www.laserpablo.com/teacherresources/files/APLabs_CCPhysics/45-Nuclear_Marbles.pdf
 Investigate phenomena and describe the structure relationships: Address prior learning by discussing
Rutherford's Gold Foil Experiment. Correct any questions or misunderstandings.
 Using mathematical expressions to represent phenomena to support explanations: Discuss the equation
in the lab: where R is the radius of the large marble, r is the radius of the small marble, N is the number of
small marbles, L is the width of the target box, H is the number of trials that resulted in at least one hit, and T
𝑝𝑎𝑡ℎ 𝑤𝑖𝑑𝑡ℎ
𝑁(2𝑅+2𝑟)
𝐻
is the total number of trials. 𝑃 =
=
= (Teacher Tip: Bowling may be useful to describe
𝑡𝑎𝑟𝑔𝑒𝑡 𝑤𝑖𝑑𝑡ℎ

𝐿
𝑇
the path width and target width part of the equation. Repeat to students that H is a yes or no question. Either
it hit, or it didn't. Don't count multiple hits on a single trial. Also, try to roll the marble as randomly as possible
as to not bias the experiment.)
Collect data and generate evidence to answer scientific questions: Carry out the investigation following
the directions, gather and collect information.
Reasoning

Using mathematical expressions to represent phenomena to support explanations: Calculate the radius
of the small marble, as well errors. (Teacher Tip: Measure and record the radius of the large marble so that
you can share that with groups. A caliper is useful for this.)
Communicating

Investigate phenomena and describe the structure relationships: in small groups, answer the following
questions:
o Why are a large number of trials necessary for a measurement like this?
o One student aimed while performing this experiment. Would his number of hits likely be larger or
o
o
o
smaller than expected? How would this effect his calculated marble radius?
In Rutherford’s Experiment, only 0.005% of alpha particles bounced back. What does that indicate
about the radius of the nuclei involved with the experiment?
How does your measurement compare with the true measurement of the marble supplied by your
teacher? List possible sources of error and how they might affect the calculated radius?
List major problems that Rutherford and his colleagues faced when attempting to calculate the size of
gold atoms.
Assessment of Student Learning
Completion of the assignment will be assessed, as will the accuracy of the calculations. Content will also be assessed in quizzes
and the unit exam.
SEP, CCC, DCI Featured in Lesson
Science Essentials (Student Performance Expectations From Appendix C, D, E)
Science Practices
Developing and Using Models
Using Mathematics and
Computational Thinking
Planning and Carrying Out
Investigations
Use representations to reflect on mechanisms of how things work.
Using mathematical expressions to represent phenomena to support explanations.
Collect data and generate evidence to answer scientific questions
Crosscutting Concepts
Scale, Proportion, and Quantity
Structure and Function
Use models to examine systems that are too small to observe directly
Investigate phenomena and describe the structure relationships
Disciplinary Core Ideas
Structure of Matter
HS-PS1-2 Construct and revise an explanation for the outcome of a simple
chemical reaction based on the outermost electron states of atoms, trends in
the periodic table, and knowledge of the patterns of chemical properties.