Atomic Structure and Periodic Table
Objective 1.1: Atomic Theory
Understand that over time technology was introduced that allowed scientists to study the atom and its structure in more detail.
Summary of Concept: The idea of the atom dates back to around 400 BC but the most relevant string of advances started in 1803 with John Dalton. As technology progressed the ability to understand more about atoms and their properties continued to develop. One major contributor to the idea of an atom is Ernest Rutherford.
Rutherford's experiment was a huge step forward in understanding the true nature of matter. Prior to his experiment, people seemed to the think that atoms were blobs of positively charged material that had some negative particles embedded within them. To test this theory, Rutherford fired positively charged alpha particles at a sheet of gold foil. He surrounded the gold with a screen that produced a flash of light whenever an alpha particle made direct contact. The experiment discovered that most of the particles made it through the gold foil (it was mostly empty space) but a small mount of particles were deflected. Seeing the particles pass through the material so easily gave Rutherford the understanding that most of the atom was empty space. To justify the deflected particles in the experiment, Rutherford concluded that atoms must have a tiny positively charged center that accounts for most of the mass. His experiment gave us the following important information about the nature of atoms:
Activities From Class: Atomic Theory Group Lesson
Simulations/Extra Resources: The Rutherford Experiment
Extension Opportunity: Create a list of 20 technologies that would not exist had no human ever discovered the true nature of the atom. Either write or record a brief summary of how the world might be different without these technologies.
See Videos Below:
Rutherford's experiment was a huge step forward in understanding the true nature of matter. Prior to his experiment, people seemed to the think that atoms were blobs of positively charged material that had some negative particles embedded within them. To test this theory, Rutherford fired positively charged alpha particles at a sheet of gold foil. He surrounded the gold with a screen that produced a flash of light whenever an alpha particle made direct contact. The experiment discovered that most of the particles made it through the gold foil (it was mostly empty space) but a small mount of particles were deflected. Seeing the particles pass through the material so easily gave Rutherford the understanding that most of the atom was empty space. To justify the deflected particles in the experiment, Rutherford concluded that atoms must have a tiny positively charged center that accounts for most of the mass. His experiment gave us the following important information about the nature of atoms:
- Atoms have a nucleus that holds almost all of the mass of the atom
- The nucleus is positively charged
- Most of the atom is empty space
Activities From Class: Atomic Theory Group Lesson
Simulations/Extra Resources: The Rutherford Experiment
Extension Opportunity: Create a list of 20 technologies that would not exist had no human ever discovered the true nature of the atom. Either write or record a brief summary of how the world might be different without these technologies.
See Videos Below:
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Objective 2.1: The Atom and the Periodic Table
Understand what an atom is and the subatomic particles that make it up. Also, must be able to use the periodic table to determine the following: protons, neutrons, electrons, atomic mass, atomic number, mass number.
Summary of Concept: An atom was introduced in previous science classes but to review is the smallest building blocks of all matter. Think of them like the letters in the alphabet. In order to make a word you must use the letters and the atoms are the letters. Which means like letters atoms make up EVERYTHING. Atoms are made up of three subatomic particles: protons, neutrons, and electrons. Students should know that the number of protons within an atom are determined by the atomic number on the periodic table. Helium, atomic number 2, has two protons. Students should know that protons are positively charged particles and are found in the nucleus of the atom. Protons are the most vital subatomic partical and contribute to the atom's identity, mass, and charge. Neutrons can be determined by subtracting the atomic number away from the mass number (atomic mass rounded to the nearest whole). This is because protons and neutrons are the only particles with significant mass. Students should know that neutrons are neutrally charged particles contribute to the atom's mass (and ultimately with stability which will be covered later in the course). Electrons are tiny negatively charged particles that orbit the nucleus of the atom in the electron cloud. In a neutrally charged atom, the number of electrons will be equal to the number of protons. Electrons do have mass but because it is so small it doesn't get counted towards the atom's mass number. The electron contributes to the charge of the atom (and reactivity which also will be covered later in the course).
Activities From Class: Parts of an Atom Notes, Atom Practice, Atomic Structure Battleship
Simulations/Extra Resources: Build an Atom, Atom Overview, An Atom's Structure
Extension Opportunity: Choose any element and make it into a superhero! Using the element's chemical and physical properties develop the a "story" for the superhero. What are their superpowers? Who is their sidekick? Who is their arch enemy? Where do they live? Be creative!
See Videos Below:
Summary of Concept: An atom was introduced in previous science classes but to review is the smallest building blocks of all matter. Think of them like the letters in the alphabet. In order to make a word you must use the letters and the atoms are the letters. Which means like letters atoms make up EVERYTHING. Atoms are made up of three subatomic particles: protons, neutrons, and electrons. Students should know that the number of protons within an atom are determined by the atomic number on the periodic table. Helium, atomic number 2, has two protons. Students should know that protons are positively charged particles and are found in the nucleus of the atom. Protons are the most vital subatomic partical and contribute to the atom's identity, mass, and charge. Neutrons can be determined by subtracting the atomic number away from the mass number (atomic mass rounded to the nearest whole). This is because protons and neutrons are the only particles with significant mass. Students should know that neutrons are neutrally charged particles contribute to the atom's mass (and ultimately with stability which will be covered later in the course). Electrons are tiny negatively charged particles that orbit the nucleus of the atom in the electron cloud. In a neutrally charged atom, the number of electrons will be equal to the number of protons. Electrons do have mass but because it is so small it doesn't get counted towards the atom's mass number. The electron contributes to the charge of the atom (and reactivity which also will be covered later in the course).
Activities From Class: Parts of an Atom Notes, Atom Practice, Atomic Structure Battleship
Simulations/Extra Resources: Build an Atom, Atom Overview, An Atom's Structure
Extension Opportunity: Choose any element and make it into a superhero! Using the element's chemical and physical properties develop the a "story" for the superhero. What are their superpowers? Who is their sidekick? Who is their arch enemy? Where do they live? Be creative!
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Objective 2.2: Bohr Model of an Atom
Be able to diagram a Bohr Model of a neutral atom using the Periodic Table.
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Summary of Concept: Students must be able to use the periodic table and follow the "rules" for drawing Bohr Models of atoms. The rules include:
Simulations/Extra Resources: Build an Atom Extension Opportunity: Use any means available to create a model of an atom. You can do this with technology, art supplies, digital media. Share your model with a video. Be sure that you discuss the limitations of creating a model to represent the atom. See Videos Below: |
"Periodic Table of Elements showing Electron Shells". Licensed under CC BY-SA 2.5 via Commons - https://commons.wikimedia.org/wiki/File:Periodic_Table_of_Elements_showing_Electron_Shells.svg#/media/File:Periodic_Table_of_Elements_showing_Electron_Shells.svg
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Objective 2.3: An Atom's Spectra
Understand that all atoms of the same element have the same atomic number and similar properties (both chemical and physical). Also, be able to understand that all elements have their own unique spectra and be able to explain the process used to obtain the spectra (in our case, the flame test). Lastly, be able to identify which subatomic particle most greatly impacts the properties.
Summary of Concept: All elements have certain chemical and physical properties that make them unique. The primary reason for this comes down to the atomic structure of the individual elements. The MOST defining subatomic particle is the proton. Think of the atomic number of an element as a recipe for creating that element. To create a hydrogen atom (atomic number 1), I would need one proton. To create a helium atom (atomic number 2), I would need two protons. To create a gold atom (atomic number 79), I would need 79 protons. This pattern is true for the entire periodic table. The number of protons (positively charged particles in the nucleus) also impacts how many electrons the atom will be able to keep attracted to the nucleus. What we end up with is each element having it's own unique recipe involving the number of protons, neutrons, and electrons that can be found within each atom.
Every element is also capable of releasing light when the atom goes from an excited state to a "ground state" (unexcited). When this happens, the unique structure of the electrons for each element will release different types of light. When measured with a spectroscope, it produces a light spectrum "fingerprint" that can be used to identify the element that was associated with releasing the light. View the emission spectra periodic table link below to see the different unique element spectra.
Activities From Class: The Unique Atom (with Flame Test Class Demo)
Simulations/Extra Resources: Emission Spectra Periodic Table, Atomic Spectra Simulation (super, high level--above what is needed for Physical Science understanding)
Extension Opportunity: Investigate how the understanding of unique atomic spectra have allowed us to make big discoveries in space and astronomy. See Videos Below:
Every element is also capable of releasing light when the atom goes from an excited state to a "ground state" (unexcited). When this happens, the unique structure of the electrons for each element will release different types of light. When measured with a spectroscope, it produces a light spectrum "fingerprint" that can be used to identify the element that was associated with releasing the light. View the emission spectra periodic table link below to see the different unique element spectra.
Activities From Class: The Unique Atom (with Flame Test Class Demo)
Simulations/Extra Resources: Emission Spectra Periodic Table, Atomic Spectra Simulation (super, high level--above what is needed for Physical Science understanding)
Extension Opportunity: Investigate how the understanding of unique atomic spectra have allowed us to make big discoveries in space and astronomy. See Videos Below:
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Objective 3.1: Ions
Understand ions by being able to:
- Use a Bohr Model of an neutral atom to create an ion.
- Explain why an atom changes to an ion.
- Explain how an atom is affected when an atom changes to an ion.
- Explain the difference between cations and anions.
- Write ionic symbols using information from Bohr Models
Summary of Concept: To be considered an atom, the atom must contain equal numbers of protons and electrons. This means that the atom has an overall neutral charge (not positive or negative). Atoms can, however, gain additional electrons, or lose electrons and does so to obtain a full outer shell. When this happens we refer to the positive or negatively charged particle as an Ion. When the atom becomes an ion the only thing that is affected is the overall charge of the atom. An atom that gains an electron and becomes negatively charged is called an anion. An atom that loses an electron and becomes positively charged is called a cation. We can easily remember the difference using this handy trick: aNion (the N tells you it is negatively charged. Ca+ion (Replacing the t with a plus sign will tell you it is positively charged).
Activities From Class: Create an Ion, What's an Ion? (Video Notes), Partner Whiteboard Practice (Ions), Big Ideas of Ions
Simulations/Extra Resources: Build and Atom, Deeper understanding of anions and cations
Extension Opportunity: Find 5 amazing chemical reactions involving cations or anions. Share videos or stories of these reactions in any form you wish.
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Activities From Class: Create an Ion, What's an Ion? (Video Notes), Partner Whiteboard Practice (Ions), Big Ideas of Ions
Simulations/Extra Resources: Build and Atom, Deeper understanding of anions and cations
Extension Opportunity: Find 5 amazing chemical reactions involving cations or anions. Share videos or stories of these reactions in any form you wish.
See Videos Below:
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Objective 3.2: Isotopes
Understand isotopes by being able to:
- Identify which subatomic changes to create an isotope
- Explain how an atom is affected when it changes to another isotope.
- Identify the most common isotopes of given elements
- Use a isotopic symbol to determine parts of an atom and help draw Bohr Models
Summary of Concept: The main ingredient for determining an element is the number of protons. But you can create different "types" of this element by changing a different ingredient... the number of neutrons. Changing the number of neutrons in an atom does not make a different element, just a different type of the same element. We call these different "types" of the same element the different isotopes. I always thought it would make more sense to call them isotopes but they are not. For example, there are many different types of Carbon. Because Carbon is atomic number 6, all of the isotopes would have 6 protons. But there could be a wide range of neutrons in different carbon isotopes. You could have carbon with a mass of 8 (it would only have two neutrons) all the the way up to carbon with a mass of 22 (which would have 16 neutrons). The different isotopes are simply different "types" of the same atom. Because different isotopes also have different amounts of neutrons, their masses are different too!
Activities From Class: Isotopes and Atomic Mass, Top Secret Atoms, Isotope Puzzle
Simulations/Extra Resources: Isotopes Quiz, Build and Atom
Extension Opportunity: Find an atom with at least 5 different isotopes. Compare and contrast the different isotopes and ways that they are used by people!
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Activities From Class: Isotopes and Atomic Mass, Top Secret Atoms, Isotope Puzzle
Simulations/Extra Resources: Isotopes Quiz, Build and Atom
Extension Opportunity: Find an atom with at least 5 different isotopes. Compare and contrast the different isotopes and ways that they are used by people!
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Objective 4.1: Characteristics and Components of Elements
Atomic number, mass number, charge and identity of an element can be determined from:
- lists of protons, neutrons and electrons
- Bohr Models of an atom, ion, or isotope.
- Isotopic or Ionic symbols
Summary of Concept: Simply using the number of protons, neutrons, and electrons, we can determine a great number of facts about an element. You can use the number of protons to identify the atomic number. Once you have the atomic number, you know which element is being discussed. From there you can identify the atomic mass of the element by adding the number of protons and neutrons. When you know the atomic mass, you can determine the isotope of the individual element. You can also determine the charge of the atom by comparing the number of protons to the number of electrons. Each proton has a positive charge and each electron has a negative charge. In neutrally charged atoms, you have the same number of protons and electrons. If we have more electrons than protons then we are dealing with a negatively charged anion. If we are dealing with more protons than electrons we have a positively charged cation.
Activities From Class: Putting it All Together (video recap), Identifying Components Practice
Simulations/Extra Resources: Build and Atom, Online Exploration of Atoms, ptable.com
Extension Opportunity: Create a fake cooking show where your only ingredients are protons, neutrons, and electrons. Use the materials to create different elements and discuss the use of those elements. For example, cook up some uranium for nuclear fission. Be creative.
See Videos Below:
Activities From Class: Putting it All Together (video recap), Identifying Components Practice
Simulations/Extra Resources: Build and Atom, Online Exploration of Atoms, ptable.com
Extension Opportunity: Create a fake cooking show where your only ingredients are protons, neutrons, and electrons. Use the materials to create different elements and discuss the use of those elements. For example, cook up some uranium for nuclear fission. Be creative.
See Videos Below:
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Objective 5.1: Periodic Law
Understand the organization of the periodic table:
- By understanding that the elements are listed in order of atomic number
- Explaining how atomic mass is affected as you travel to the right and down on the table
- Explaining how volume is affected as you travel down on the table
- Identifying location of halogens, noble gases, alkali metals and alkaline earth metals
- Explaining why and how elements within the same family/group have similar physical and chemical properties
- Identifying the most reactive families/groups and what subatomic particle is credited for determining reactivity
- Using the Periodic Table to identify number of valence electrons, electron shells, and ionic charge
Summary of Concept: The atomic number is equal to the amount of protons in the atom's nucleus. The elements on the periodic table are listed in order of increasing atomic number which also means that as you travel further to the right and down the mass of the nucleus also increases. Elements are located in vertical columns which we call families or groups. Elements within the same family or group have similar physical and chemical (ie. reactivity) properties because the valence electron configuration is the same. We can use the group number to help us determine the number of valence electrons in a given atom as well as its ionic charge. Also, elements are located in horizontal rows which we call periods. The period number that an element is located tells us how many electron shells present within that atom.
Activities From Class: How is the Periodic Table Organized?, Periodic Table Scavenger Hunt, How should it React?, Family Resemblance Puzzle
Simulations/Extra Resources: Learn the groups of the Periodic Table, Guide to the periodic table
Extension Opportunity: Create an "interview with the elements" talk show video. Interview an element from the main groups of the periodic table and demonstrate their properties through humorous interviews. For example... alkali metals are highly reactive so they would go crazy and be completely unstable. Have fun and be creative with this!
See Videos Below:
Activities From Class: How is the Periodic Table Organized?, Periodic Table Scavenger Hunt, How should it React?, Family Resemblance Puzzle
Simulations/Extra Resources: Learn the groups of the Periodic Table, Guide to the periodic table
Extension Opportunity: Create an "interview with the elements" talk show video. Interview an element from the main groups of the periodic table and demonstrate their properties through humorous interviews. For example... alkali metals are highly reactive so they would go crazy and be completely unstable. Have fun and be creative with this!
See Videos Below:
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Objective 5.2: Metals, Nonmetals and Metalloids (semi-metals)
Understand the types of elements found on the periodic table by:
- Identifying where metals, nonmetals and metalloids (semi-metals) are located within the table
- Describing physical and chemical properties of metals, nonmetals, and metalloids (semi-metals)
Summary of Concept: The periodic table is further organized by grouping types of elements (ie. metals, nonmetals and semi-metals). Metals are located towards the left side of the table while nonmetals are located on the right. Metalloids are found in a stair step pattern (see green shaded elements in the picture above) towards the right but ultimately separate the metallic from the nonmetallic elements. Metals and nonmetals have distinct physical and chemical properties while metalloids (semi-metals) have properties of both types of elements.
Activities From Class: Metal or Nonmetal? Lab
Simulations/Extra Resources: Metals and Nonmetals, Properties of Metals and Nonmetals
Extension Opportunity: Investigate any element to try to figure out everyday uses. Focus on how the type of element contributes to its physical properties and how that relates to its usage.
See Videos Below:
Activities From Class: Metal or Nonmetal? Lab
Simulations/Extra Resources: Metals and Nonmetals, Properties of Metals and Nonmetals
Extension Opportunity: Investigate any element to try to figure out everyday uses. Focus on how the type of element contributes to its physical properties and how that relates to its usage.
See Videos Below:
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