Grade 8
Science
Unit: 02
Lesson: 01
Suggested Duration: 8 days
Atomic Structure
Lesson Synopsis:
In this lesson, students will describe the structure of the atom including the masses, locations, and electrical charges of
subatomic particles. Students will use the periodic table to collect the information needed to construct models of
elements/atoms. Students will analyze and interpret information from atom/element models and the periodic table to
understand that protons determine the identity of an element. Students are only accountable for the location of valence
electrons at this time. Chemical reactivity will be addressed in a future unit.
TEKS:
8.5
Matter and energy. The student knows that matter is composed of atoms and has chemical and physical properties.
The student is expected to:
8.5A
Describe the structure of atoms, including the masses, electrical charges, and locations, of protons and neutrons in
the nucleus and electrons in the electron cloud. Readiness Standard
Identify that protons determine an element’s identity and valence electrons determine its chemical properties
including reactivity. Readiness Standard
8.5B
Scientific Process TEKS:
8.2
Scientific investigation and reasoning. The student uses scientific inquiry methods during laboratory and
field investigations. The student is expected to:
8.2C
Collect and record data using the International System of Units (SI) and qualitative means such as labeled
drawings, writing, and graphic organizers.
8.3
8.3B
8.3C
8.3D
8.4
8.4A
Scientific investigation and reasoning. The student uses critical thinking, scientific reasoning, and
problem-solving to make informed decisions, and knows the contributions of relevant scientists. The
student is expected to:
Use models to represent aspects of the natural world such as an atom or a molecule, space, or a geologic
feature.
Identify advantages and limitations of models such as size, scale, properties, and materials.
Relate the impact of research on scientific thought and society, including the history of science and
contributions of scientists as related to the content.
Scientific investigation and reasoning. The student knows how to use a variety of tools and safety
equipment to conduct science inquiry. The student is expected to:
Use appropriate tools to collect, record, and analyze information, including lab journals/notebooks,
beakers, meter sticks, graduated cylinders, anemometers, psychrometers, hot plates, test tubes, spring
scales, balances, microscopes, thermometers, calculators, computers, spectroscopes, timing devices, and
other equipment as needed to teach the curriculum.
GETTING READY FOR INSTRUCTION
Performance Indicator(s):
•
Draw two different atoms, and label their structures. Under each drawing, describe, in writing, the structure of the
atoms including the masses, electrical charges, and locations of the protons, neutrons, and electrons; as well as
the atomic number and mass number of each atom. Include an explanation of how each atom can be identified by
the representation. (8.2C; 8.3B; 8.5A, 8.5B)
1C; 5B, 5G
Key Understandings and Guiding Questions:
•
•
Atoms are composed of subatomic particles.
— How are atoms structured?
— What are the locations, masses, and electrical charges of the subatomic particles?
— Where are valence electrons located?
Protons determine the atom’s identity.
— How is the identity of an element determined?
— What is the importance of protons?
— Why are protons used to determine the identity of an element?
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06/10/13
page 1 of 4
Grade 8
Science
Unit: 02 Lesson: 01
Vocabulary of Instruction:
•
•
•
subatomic particle
proton
neutron
•
•
•
electron
valence electron
atom
•
•
electron cloud
nucleus
Materials:
See Notes for Teacher section for materials.
Attachments:
•
•
•
•
•
•
•
•
•
•
•
Handout: What’s Inside? (1 set of instructions per student, see Advance Preparation)
Teacher Resource: PowerPoint: Atoms: Development of the Atomic Theory
Handout: Atomic Structure Notes (1 per student)
Teacher Resource: Atomic Structure Notes KEY
Teacher Resource: PowerPoint: Structure of an Atom
Teacher Resource: Atomic Structure Matching (1 set per pair, see Advance Preparation)
Handout: Drawing Atomic Structures (1 per student)
Teacher Resource: Drawing Atomic Structures KEY
Handout: Blank Atom Model (1 per student if used as assessment, see Advance Preparation)
Handout: Decoding Models (1 per student)
Teacher Resource: Evaluate Instructions PI
Advance Preparation:
1. Prior to Day 1:
• If you did not supply a periodic table for students during the Unit 01 science notebooking set up, conduct a
web search for TEA STAAR science reference materials (Click on Grade 8 Science Reference Materials.).
Download and print a STAAR Grade 8 Science Reference Materials periodic table for each student to include
in their science notebooks.
• Conduct a web search for “Powers of 10”. You may wish to include Florida State University (fsu.edu) in your
search.
• Prepare a What’s Inside box for each pair of students. Any small cardboard box with a lid will work. For
example: The cardboard boxes that pieces of jewelry come in would work. The US Postal Service has flat rate
boxes for free. The small box is about the size of a VHS tape. Place an object, or several of the same objects,
in the box, and seal it. Use plenty of tape or glue to keep the boxes closed. Clear packing tape also works
well. Some suggested objects for the boxes include: a small rubber ball, small and large marble, wooden
block, washers, large nail, crayon, etc.
• Print and cut apart enough copies of the Handout: What’s Inside? to have one set of instructions for each
pair of students. There are three sets of instructions per page.
2. Prior to Day 2: Cut enough 20 cm strips of paper for each student to have one piece.
3. Prior to Day 3: Prepare a class set of manipulatives using the Teacher Resource: Atomic Structure Matching.
Prepare enough for each pair of students to have one set. Each set will include one half of page of labels on page
1 and all of page 2. Precut the labels on page 1. Printing on cardstock and laminating is recommended. Place
each set in a resealable, plastic bag.
4. Prior to Day 5: Prepare a class set (1 per student) using the Handout: Blank Atom Model. Printing on cardstock,
and laminating is recommended. Collect materials and various manipulatives for students to use in modeling
protons, neutrons, and electrons, such as plastic chips, centime cubes, beans, peas of various sized, etc. You will
need a variety of materials and sizes per group.
5. Prior to Day 6: Prepare a set of Petri dish models for each station. Each model should be of a different atom. Use
colored beads of two sizes and three colors. Two kinds of beans of similar size and of different colors will be
needed, although a smaller bean or dried pea may be used instead such as kidney beans, navy beans, pinto
beans, or green peas. Use chenille stems to form a nucleus to hold the protons or neutrons. There can be more or
less stations, depending on the number of students per group/class.
Protons
For example:
©2013, TESCCC
Neutrons
06/10/13
Electrons
page 2 of 4
Grade 8
Science
Unit: 02 Lesson: 01
Secure the top to the bottom of the Petri dish with several wraps of tape. Use masking tape to label each dish with
a letter: A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, etc. (Example shows elements # 1-15.) Create a key to show
which elements are in the labeled containers.
6. Prepare attachment(s) as necessary.
Background Information:
This unit bundles TEKS addressing the properties and structure of atoms.
Prior to this unit, students have had no exposure to atomic structure. During this unit, students will describe properties and
the structure of an atom including: mass/size comparisons, electrical charges, and locations of subatomic particles.
Students are only expected to identify valence electrons in the terms of location at this time. Students will be able to
identify elements based on the number of protons in an atom. Students are expected to interpret the relationship between
the information on the periodic table and the atomic structure of atoms/elements for the purpose of constructing/decoding
models. The arrangement of the periodic table, as well as the role of valence electrons and reactivity, will be addressed in
a future unit.
STAAR Note:
Atomic structure will be tested as Readiness Standards under Reporting Category 1: Matter and Energy on the Grade 8
STAAR Assessment.
GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT
Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners.
The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus
Document for this unit. Instructors are encouraged to create original lessons using the Content Creator in the Tools Tab located at the top of the page.
All originally authored lessons can be saved in the “My CSCOPE” Tab within the “My Content” area.
INSTRUCTIONAL PROCEDURES
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06/10/13
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Instructional Procedures
Notes for Teacher
ENGAGE/EXPLORE – What’s Inside?
NOTE: 1 Day = 50 minutes
Suggested Day 1
1. Distribute the What’s Inside boxes and a copy of the Handout: What’s
Inside? (see Advance Preparation) to each pair of students. Instruct
students not to open the boxes. Do not share what is inside the boxes with
students.
2. Ask students to read the handout and answer any questions they may
have about the directions.
3. Allow students about 15 minutes to complete the activity as directed on the
handout.
4. Monitor students and assist as necessary, checking students’ observations
and conclusions about the object’s shape and size. Do not confirm nor
deny the identity of the object inside the box, but encourage students to
use evidence to justify their conclusions.
Grade 8
Science
Unit: 02 Lesson: 01
Materials:
• What’s Inside? Boxes (see
Advance Preparation, 1 per pair of
students)
• box with lid (cardboard, see
Advance Preparation, 1 per
pair)
• object (to place in box , see
Advance Preparation, per box)
• tape or glue (clear and masking,
per group)
Attachments:
• Handout: What’s Inside? (see
Advance Preparation, 1 set of
instructions per pair of students)
Instructional Notes:
Prepare boxes in advance of class.
Students are not to open their box or be
told what is inside it, to enable them to
think about how scientists use indirect
evidence to come up with theories for
phenomena otherwise invisible to the
naked eye.
Science Notebooks:
Students record their observations of
the What’s Inside Box and draw
inferences on what the items inside may
be. Students should illustrate the object
as well. Conclusions should be justified
with evidence.
EXPLAIN – Developing Explanations
1. Facilitate a class discussion in which students reflect on the following
questions:
• Without the option of opening the box, what tool(s) might make
the identification of what is in the box easier? Students may not
know any of equipment. Electron microscopes or x-rays may be
suggested. Answers will vary.
• What clues did you use to determine what is inside? Answers will
vary, but may include sound, vibration, heft, how the object moved,
etc.
Suggested Day 1 (continued)
Instructional Note:
Use an instructional strategy, such as
Think-Pair-Share, to allow students to
share and process by speaking and
listening.
2. Instruct students to share their drawings and ideas with other students
utilizing the following questions.
• What is in your box?
• How do you know… Students should cite observational evidence for
their claim.
3. Ask for a few students to share their drawings and ideas with the rest of
the class.
4. Facilitate a discussion including the following questions:
• How do scientists use indirect evidence to develop explanations
or theories? Based on observations and experiences,
scientists
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develop models, etc.
• What are some phenomena that scientists cannot see? Distant
11 P
12 N
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