Download UC Irvine FOCUS! 5 E Lesson Plan Title: Marble Isotope Lab Grade

UC Irvine FOCUS!
5 E Lesson Plan
Title: Marble Isotope Lab
Grade Level and Course: 8th Grade Physical Science and 9-12 High School Chemistry
Materials:
Red, blue and yellow marbles (25 each)
Instructional Resources Used: (concept maps, websites, think-pair-share, video
clips, random selection of students etc.)
 Think-pair-share - Students will watch videos, record all thoughts and
perceptions, share with another student and then share out to class. Teacher
will record all thoughts on the board.
 Venn diagram-Students will create venn diagrams for two isotopes C-14 and
C-12, neutral atoms.
California State Standards: (written out)
8th Grade Physical Science
7. The organization of the periodic table is based on the properties of the elements
and reflects the structure of atoms. As a basis for understanding this concept:
b. Students know each element has a specific number of protons in the
nucleus (the atomic number) and each isotope of the element has a different
but specific number of neutrons in the nucleus.
Investigation and Experimentation
9. Scientific progress is made by asking meaningful questions and conducting
careful investigations. As a basis for understanding this concept and addressing the
content in the other three strands, students should develop their own questions and
perform investigations. Students will:
e. Construct appropriate graphs from data and develop quantitative
statements about the relationships between variables.
9-12 High School Chemistry
11. Nuclear processes are those in which an atomic nucleus changes, including
radioactive decay of naturally occurring and human-made isotopes, nuclear fission,
and nuclear fusion. As a basis for understanding this concept:
c. Students know some naturally occurring isotopes of elements are
radioactive, as are isotopes formed in nuclear reactions.
f. * Students know how to calculate the amount of a radioactive substance
remaining after an integral number of half-lives have passed.
Lesson Objectives:
a. Students will successfully follow directions and complete the lab.
b. Students will be able to differentiate between isotopes of the same
element.
c. Students will use correct notation to express isotopes.
Differentiation Strategies to meet the needs of diverse learners:
 English Learners: Students will be divided in appropriate level learning groups,
higher level EL students with lower level EL students. Prior to the lab, they will
define the term “isotope” and complete the short attached worksheet in their
groups. Here are three isotopes of an element:
12
13
14
6 C
6 C
6 C
a. The element is: __________________
b. The number 6 refers to the _________________________
c. The numbers 12, 13, and 14 refer to the ________________________
d. How many protons and neutrons are in the first isotope? ______________
e. How many protons and neutrons are in the second isotope? ____________
f. How many protons and neutrons are in the third isotope? _____________

Special Education: Using the above example, the teacher will have the
students draw the nuclei of the isotopes and have the students verbalize the
differences they see.
 GATE: Students will research the isotopes in the lab and report on the halflife of each.
ENGAGE
 Describe how the teacher will capture the students’ interest.
o Students will watch the short video clip
http://www.youtube.com/watch?v=Jdtt3LsodAQ&feature=related
o Students write down what they see. They will then pair with a group
member to compare thoughts and finally will share out to the class
their understanding of the clip. Use of venn diagrams could help in
their descriptions.
 What kind of questions should the students ask themselves after the
engagement?
a. If all of the atoms are hydrogen, what makes them different?
b. How are all three atoms the same?
EXPLORE
 Describe the hands-on laboratory activity that the students will be doing.
Students will be given bags with different numbers of red marbles
representing protons, blue marbles representing neutrons and yellow
marbles representing electrons. Students will build the nucleus for
each of the atoms and then determine the element (based on number
of “protons”) and the atomic mass of the atom (protons + neutrons).
Students will record their information in the data table.
 List the “big idea” conceptual questions that the teacher will ask to focus the
student exploration.
a. If there are two atoms of the same element but they have different
masses, what is the reason for the different masses?
b. Can two different elements have the same atomic mass?
EXPLAIN
 What is the “big idea” concept that students should have internalized from
doing the exploration?
An element is defined by its atomic number, i.e., the number of
protons in the nucleus, whereas its mass is the sum of the protons and
neutrons in the nucleus. Atoms of the same element can have
different masses based on the number of neutrons in the nucleus.
 List the higher order questions that the teacher will ask to solicit student
explanations for their laboratory outcomes, and justify their explanations.
a. Can different elements have the same mass? Why or why not?
b. Does the number of electrons affect the mass of the isotopes? Why
of why not?
EXTEND
 Explain how students will develop a more sophisticated understanding of the
concept.
Students will research two different isotopes of the same element, one
stable and one non-stable. Students will design and build a poster
explaining the two isotopes, how they are the same and how they are
different.
 How is this knowledge applied in our daily lives?
On the poster, students will draw or cut out pictures of the current
uses and applications of the two isotopes. For the GATE student, they
will explain
half-life and how it is determined.
EVALUATE
 How will the student demonstrate their new understanding and/or skill?
Students will accurately fill-in the data table and answer the lab questions.
Additionally, students will be able to identify examples of isotopes of the
same element from a collection of isotopes on the end of unit test and
benchmark exams.
 What is the learning product for the lesson?
a. Successful completion of the lab.
b. Correctly answering the lab questions.
c. Accurate completion of the presentation board.
Background Knowledge for the Teacher:
Isotopes are basically the same element with a different number of neutrons. The
nucleus of every atom is made up of neutrons and protons. While neutrons don’t
have a charge they do important work such as helping to bind the positive charged
protons together via the strong force. Isotopes can have different numbers of
protons but the basic elemental structure remains the same. For example deuterium
will have one more neutron than normal hydrogen but it will still be considered
hydrogen. The only thing that will change is the atomic weight.
What is the importance of isotopes? Isotopes have a special set of properties called
nuclear properties. For example certain isotopes are more prone to radioactive
decay making them ideal materials to use in nuclear reactions.
Source: http://www.universetoday.com/73717/what-are-isotopes/
Student pages are attached.
Marble Isotopes
Background Info: Every atom of the same element has the same number of protons.
Different atoms of the same element can have different numbers of neutrons. Because
the protons and neutrons make up the mass of the atom, different atoms of the same
element can have different masses! These are called isotopes.
For example:
Lithium (Li) has two isotopes. Both isotopes have 3 protons (atomic number 3), but one
has 3 neutrons and the other has 4 neutrons!
Example A: The Li isotope with 3 neutrons has a mass number of 6 (3p + 3n)
Symbol is 36Li
Name is Lithium-6
Example B: The Li isotope with 4 neutrons has a mass number of 7 (3p + 4n)
Symbol is 37Li
Name is Lithium-7
Purpose: In today’s activity you will learn what an isotope is and how to write the
correct symbols and names of various isotopes.
Procedure: Working with your partner(s), count the number of protons (red marbles),
neutrons (blue marbles) and electrons (yellow marbles) in each baggie and enter the data
in the table below. Use your periodic table to identify the element. Following the
example of lithium isotopes given above, write the symbol and name of each isotope.
Data Table:
Bag #
# of
Protons
# of
Neutrons
# of
Electrons
Atomic Mass
(ave. atomic
mass)
Isotope
Mass
Atomic
Number
Ex. A
Ex. B
1
2
3
4
5
6
7
8
9
10
11
3
3
3
4
3
3
6.9
6.9
6
7
3
3
Nuclear
Symbol
6
3
7
3
Li
Li
Isotope Name
Lithium-6
Lithium-7
Questions:
1. What are some uses of isotopes?
2. How many hydrogen isotopes did you find?
a. How are they the same?
b. How are they different?
3. How many neutrons does 817O have?
4. What is the correct nuclear symbol for carbon-14?
5. What does the 35 in the name chlorine-35 represent?
6. Cobalt-60 is used as radiation therapy for cancer. How many protons and
neutrons does cobalt-60 have?
7. Iodine-131 is used to detect thyroid problems. How is iodine-131 the same
as iodine-126?
8. How is iodine-131 different from iodine-126?
Summary Paragraph: Write a paragraph summarizing what you learned in today’s
activity about isotopes. Explain what an isotope is and how different isotopes of one
element are alike and different.