Atomic Structure (SAM) (9-page, 2-day activity)

Interactive, scaffolded model

Overview and Learning Objectives

In this activity students explore the structure and properties of atoms. They construct models of atoms with properties of particular mass and charge; create models of atoms with different stabilities by adding or subtracting neutrons, protons, and electrons to a model atom; and determine that the same element may have varying number of neutrons and these form isotopes.

Students will be able to:

• Explore the probabilistic electron orbital model to help explain where electrons are most likely to be found.

• Explain that all atoms have similar structure, differing only in the number of protons, neutrons, and electrons.

• Build models of atoms and ions and identify patterns in numbers of protons and neutrons in stable nuclei and ions.

• Describe simple patterns in the periodic table.

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Classroom Practice

Teacher Guide:

http://sam.concord.org/publications/teacher-guides/atomic_structure.ver6.pdf

Biologists: It is useful for students to understand (especially if they have not taken chemistry first) that all biological structures are made of atoms and molecules. Biological functions are due to the number and arrangements of atoms and electrons. It is important, therefore, to be familiar with the structure of atoms.

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Central Concepts

Key Concept:

Atoms are the basic building block of matter. Atoms are composed of three types of particles: protons, neutrons, and electrons. Protons and neutrons are responsible for mass. Protons determine atomic number. Protons have a positive charge and electrons have a negative charge.

Additional Related Concepts

Concept Map Available

Physics/Chemistry

• Atom
• Electron
• Ion
• Isotope
• Mass
• Neutron
• Periodic Table
• Proton

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Textbook References

• Biology (Miller and Levine) Prentice Hall 5th Edition - Unit I: Chapter 3 - Introduction to Chemistry
• Biology (Prentice-Hall) New York Edition - Chapter Two - The Chemistry of Life
• Biology: Concepts and Connections (Pearson) 5th Edition - Chapter 2: The Chemical Basis of Life
• Biology: Exploring Life - Chapter 4: The Chemical Basis of Life
• Biology: The Dynamics of Life - Chapter 6: The Chemistry of Life
• BSCS Blue (8th Edition) - Chapter 17: The Origin of Life
• BSCS Blue (8th Edition) - Chapter 1: The Chemistry of Life

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Benchmarks and Standards

AAAS

• THE PHYSICAL SETTING: ENERGY TRANSFORMATIONS - Different energy levels are associated with different configurations of atoms and molecules (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: FORCES OF NATURE - There are two kinds of charges-positive and negative. (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - Atoms are made of a positive nucleus surrounded by negative electrons (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - Neutrons have a mass that is nearly identical to that of protons, but neutrons have no electric charge (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - The nucleus, a tiny fraction of the volume of an atom, is composed of protons and neutrons, each almost two thousand times heavier than an electron (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - The number of positive protons in the nucleus determines what an atom's electron configuration can be and so defines the element (Full Text of Standard)
  
  
• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - When elements are listed in order by the masses of their atoms, the same sequence of properties appears over and over again in the list (Full Text of Standard)
  
  

NSES

• Physical-Science: Energy/Matter Interactions - 1 Waves, including sound and seismic waves, waves on water, and light waves, have energy and can transfer energy when they interact with matter (Full Text of Standard)
  
  
• Physical-Science: Matter Structure/Properties - 2 An element is composed of a single type of atom (Full Text of Standard)
  
  

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Extensions and Connections

Fermi Lab's ARISE suggests the following enhancement to the SAM unit:

http://www.concord.org/~barbara/SAM/ARISE/ARISE_SAM_Atom.pdf

This activity can also be used to explore radiation. Concept map is located at:

http://www.concord.org/~barbara/molo/molo_concept_maps/radioactivity.html

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Additional Info

Additional Background

The following quote might be useful for engaging the class in a discussion. "If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms -- little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another." (Feynman, Leighton, & Sands, 1963, v1, p. 2)

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Activity Credits

Created by CC Project: Molecular Logic using Molecular Workbench

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Requirements

• Adobe Flash Plugin
• Java 1.5+ - Java 1.5+ is available for Windows, Linux, and Mac OS X 10.4 and greater. If you are using Mac OS X 10.3, you can download MW Version 1.3 and explore within it instead.
• QuickTime for Java - Important Note: Due to a recent QuickTime update, you may not be able to see some models with embedded Flash components. We are currently trying to develop a workaround.

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