Download Mystery Isotopes

Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 51015
Mystery Isotopes
Through this engaging activity students work as a group to create models of isotopes with stickers and construction paper. Students also use models
created by their peers to analyze the number of subatomic particles and determine isotopes' names. All worksheets and data collection sheets are
included.
Subject(s): Science
Grade Level(s): 8, 9
Intended Audience: Educators
Suggested Technology: Basic Calculators
Instructional Time: 1 Hour(s)
Freely Available: Yes
Keywords: isotope, isotopes, atomic structure, atom, subatomic particles, protons, neutrons, electrons
Instructional Design Framework(s): Direct Instruction, Cooperative Learning
Resource Collection: CPALMS Lesson Plan Development Initiative
ATTACHMENTS
Mystery Isotope Lab.docx
Mystery Isotope Strips.docx
Isotope Worksheet.docx
KeyMystery Isotope Lab.docx
Atoms and the Periodic Table Chart.docx
KeyIsotope Worksheet.docx
LESSON CONTENT
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will be able to create a Bohr Model of Nitrogen and Carbon isotopes.
Students will be able to identify and name isotopes through analyzing structure (arrangement of protons, neutrons, and electrons).
Students will be able to compare and contrast isotopes of the same element.
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should know that atoms are composed of subatomic particles: protons, neutrons, and electrons. They should know how to determine the number and
placement of subatomic particles. They should be able to create a Bohr model of an atom of an element on the periodic table.
Guiding Questions: What are the guiding questions for this lesson?
1. Atoms are the smallest unit of matter...but what are the parts of an atom?
2. How are they arranged?
3. Are all atoms of the same element exactly the same?
Suggested Answers:
PROTONS-An element's atomic number tell the number of protons, protons are found in the nucleus of an atom;
ELECTRONS-are found outside the nucleus in the electron cloud, the number of electrons in a neutrally charged atom/isotope are the same as the number of
page 1 of 4 proton, In Bohr's model...the first energy level of an atom/isotope holds up to 2 electrons, the second energy level holds up to 8 electrons, and the third energy level
can hold up to 18 electrons;
NEUTRONS-To calculate the number of neutrons use the formula: Protons + Neutrons = the atomic mass, the mass of an atom is in the nucleus...protons +
neutrons; Atoms of the same element have the same number of protons, but they don't always have the same number of neutrons.
ISOTOPES are atoms of the same element, with the same number of protons, but different numbers of neutrons.
Teaching Phase: How will the teacher present the concept or skill to students?
Teacher will discuss atoms with students.
"Atoms are the smallest unit of matter...but what are the parts of an atom? How are they arranged? Let's draw a Bohr's model of the isotope Oxygen-18."
Teacher will model how to a Bohr's diagram model of Oxygen-18. (The 18 of Oxygen-18 represents the mass.)
While modeling how to draw a Bohr's diagram model of Oxygen-18, the teacher will prompt the class with the following questions:
How do I figure out the number of protons? Where do they belong?
How do I determine the number of neutrons?
What's the atomic mass of Oxygen-18?
Where should I place the neutrons on our model?
How do I determine the number of electrons? Where do they go?
How many electrons fill up the first energy level, the second...etc.
(Ans. Oxygen-18 has 8 protons in the nucleus. The number of protons is determined by the atomic number. Oxygen-18 has a mass of 18. To calculate neutrons use
the formula P+N=mass. Therefore, there are 10 neutrons in the nucleus of Oxygen-18. The number of negatively charge electrons are the same and the number of
positively charge protons. Therefore, there are 8 electrons in the electron cloud. There are 2 electrons on the first energy level, and 6 on the second energy level.)
While modeling how to draw the isotope Oxygen-18, don't forget to draw a key to differentiate between the three subatomic particles.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Students will be divided into 6 groups. Teacher will pass out a "Mystery Isotope Strip" and a piece of construction paper to each group. Teacher will also pass out the
Mystery Isotope Lab data sheet to each student. Students will also need periodic tables.
Groups will make a model of their given isotope on the construction paper.
1. They will title the construction paper: Mystery Isotope # ____. (Make sure they do NOT write the name of their Mystery Isotope.)
2. Groups will figure out the number of protons, neutrons, and electrons in their isotope and record this information on the lab data sheet.
3. Once the students figure out the number of each particle they will need for their model, they will collect the correct number of stickers. Make sure students get one
additional sticker per particle (protons, neutrons, and electrons) than needed for a key.
4. Groups will use the stickers to create a Bohr model of the isotope on the construction paper. They need to include a key.
Teacher will monitor and prompt groups as needed. They will also check isotope models created before the exchange.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the
lesson?
Groups rotate isotope models and complete the Mystery Isotope Lab data sheet.
Isotope models will be rotated until each group has completed the information on each model.
Students will answer the follow-up questions on the Mystery Isotope Lab worksheet.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Teacher will lead a short discussion:
So what happens if Carbon-12 gained a neutron? (Ans: The mass would change, it would become Carbon-13.)
And what about if Carbon-12 gained a proton? (Ans: It wouldn't be carbon anymore. If carbon gains a proton it would now have 7 protons and would be nitrogen. It
would become Nitrogen-13.)
Are all atoms of the same element exactly the same? Explain. (Suggested Ans: No. All atoms of the same element have to have the same number of protons. However,
they can have different numbers of neutrons. Neutrons only affect the mass of an atom. Atoms of the same element with different masses (different neutrons) are
called isotopes.)
Summative Assessment
Lab worksheet:
Suggested grading: Students earn up to 45 points
See the Answer Key for "Mystery Isotope Lab"
Were the isotopes properly identified?
What would happen if Carbon-12 gained a neutron?
What would happen if Carbon-12 gained a proton?
Formative Assessment
While modeling how to draw a Bohr diagram model of Oxygen-18, the teacher will prompt the class with the following questions:
How do I figure out the number of protons? Where do they belong?
How do I determine the number of neutrons?
What's the atomic mass of Oxygen-18?
Where should I place the neutrons on our model?
How do I determine the number of electrons? Where do they go?
How many electrons fill up the first energy level, the second...etc.
page 2 of 4 Teacher will also check isotope models created by groups before they exchange.
Feedback to Students
Teacher will check isotope models before groups exchange. Students will have the opportunity to fix any errors.
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations: Group students in mixed ability groups.
Check-in and monitor groups as they are working.
Extended modeling as needed.
Use visual aids.
Use the optional worksheet "Atoms and the Periodic Table Chart" to build prior knowledge before the lab.
Extensions: Use the "Isotope Worksheet" as homework.
Research uses of isotopes. (Suggested Answers: used to date fossils and rocks, used in medical research and treatment.)
Research uses and/or the half-lives of specific isotopes.
Determine the stability/instability of various isotopes. Which isotopes are more likely to go through radioactive decay?(Suggested Answer: When atoms have similar
numbers of protons and neutrons they tend to be stable. When they have a greater difference between the number of protons and neutrons they are unstable and more
likely to be affected by radioactive decay.)
A similar lab could be used to create and model ions.
Suggested Technology: Basic Calculators
Special Materials Needed:
Worksheets:
"Mystery Isotope Lab" --- one per student
"Mystery Isotope Strips"
Construction Paper
Stickers in various colors (Colored dot stickers, colored star stickers, etc.)
Markers
Periodic Table
Further Recommendations:
I've had students rotate the isotopes models on the construction paper around the room. However, it has also been successful to have the students rotate around the
room from one isotope model to the next.
You can be as creative as you'd like for the stickers in this lab. I've used flowers, frogs, etc. I usually use whatever is easily assessable as long as there is enough of
the same sticker type/color for the subatomic particle (e.g. neutrons). Make sure to have enough on hand for the key.
Sample Bohr Model from Brittanica http://media-3.web.britannica.com/eb-media/09/149209-004-E4AA2D63.jpg
Bohr atomic model: nitrogen atom. Art.Encyclopedia Britannica OnlineWeb. 31 Jul. 2013.
Additional Information/Instructions
page 3 of 4 By Author/Submitter
SOURCE AND ACCESS INFORMATION
Contributed by: Sarah Velasco
Name of Author/Source: Sarah Velasco
District/Organization of Contributor(s): Miami-Dade
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
LAFS.68.RST.3.7:
SC.8.P.8.7:
Description
Integrate quantitative or technical information expressed in words in a text with a version of that information expressed
visually (e.g., in a flowchart, diagram, model, graph, or table).
Explore the scientific theory of atoms (also known as atomic theory) by recognizing that atoms are the smallest unit of
an element and are composed of sub-atomic particles (electrons surrounding a nucleus containing protons and
neutrons).
Remarks/Examples:
Florida Standards Connections: MAFS.K12.MP.4: Model with mathematics.
LAFS.910.RST.3.7:
SC.912.P.8.4:
Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and
translate information expressed visually or mathematically (e.g., in an equation) into words.
Explore the scientific theory of atoms (also known as atomic theory) by describing the structure of atoms in terms of
protons, neutrons and electrons, and differentiate among these particles in terms of their mass, electrical charges and
locations within the atom.
Remarks/Examples:
Explain that electrons, protons and neutrons are parts of the atom and that the nuclei of atoms are composed of
protons and neutrons, which experience forces of attraction and repulsion consistent with their charges and
masses.
Florida Standards Connections: MAFS.K12.MP.4: Model with mathematics.
page 4 of 4