• Inform students that the slide presentation is designed to

• reestablish their familiarity with the concept of matter, and
• introduce them to the structure of the Periodic Table of the Elements.

Note: Students have come in contact with the concept of matter in middle school since the first CELL of sixth grade: Properties of Matter.While students have had brief exposure to the Table in past LabLearner experiences, we will develop their understanding further in this CELL.

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• Tell students that
• • matter is anything that takes up space and has mass, and
  • everything, everywhere is composed of matter – not just on Earth, but across the solar system and Universe.

  Note: In the next Investigation, we will expand upon this idea by introducing the concept of the Big Bang.

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• Tell students that
• • matter is anything that takes up space and has mass,
  • an element is a type of matter that cannot be broken down into another substance by chemical reactions,
  • Dmitri Mendeleev was a Russian scientist that arranged the known elements of the time into what we now use as the basis for our modern Periodic Table of the Elements,
  • Mendeleev did his work in the early 1800s
  • there are currently 118 known elements, 
  • many of the elements, particularly nearer the bottom of the Table, are man-made and do not occur in nature, and
  • they will begin to explore information about two of the elements, Boron and Aluminum, on the next slide.
  • Click the right arrow to highlight the elements Boron and Aluminum.

  Note: An element is different than a compound like H₂O, for example, which can be broken down into the elements hydrogen (H) and oxygen (O).

   

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• Tell students that
  • while various Periodic Tables provide different amounts of information about the elements, the most important information is depicted in the boxes on this slide,
  • the atomic symbol is represented by one, two, or three letters,
  • the atomic number is the number at the top of the box (Click the right arrow for animation.), and
  • the atomic mass, sometimes called atomic weight, is the number at the bottom of the box (Click the right arrow for animation.)
• Ask students to reference the Periodic Table of the Elements in their SDRs.
• Call out an element and have students name the atomic symbol, atomic number, and atomic mass. Repeat this procedure until students are comfortable locating the information.

Note: The Periodic Table of the Elements is referred to in various manners in common usage. The following terms are typical:

• Periodic Chart of the Elements
• Periodic Table of Elements
• Periodic Table
• The Table
• Others

Note: The importance of the Atomic Number and Atomic Mass will be discussed further in Investigation 2 of this CELL. 

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• Tell students that
  • the Periodic Table has 18 vertical columns called groups (Click the right arrow for animation.), and
  • the Periodic Table has seven horizontal rows called periods (Click the right arrow for animation.).
• Ask students to reference the Periodic Table of the Elements in their SDRs.
• Call out a Period and Group and have students name the element, atomic symbol, atomic number, and atomic mass. Repeat this procedure until students are comfortable locating the information.
• Note: The point is not to have students memorize data regarding the elements but to be able to find this data quickly on the Periodic Table)

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• Tell students that
• • elements are not randomly placed on the Periodic Table, but rather are grouped by their physical and chemicalproperties,
  • a major distinction between the elements is whether they are metals or nonmetals, and
  • elements between the metals and nonmetals are metalloids.

  Note: A major distinction between the elements is whether they are metals or nonmetals. Differences between metals and nonmetals will be explored in upcoming Investigations as follows:

  Investigation 2: Chemical reactivity, reaction with an acid, will be compared between various elements.

  Investigation 3: Electrical conductivity, the ability to conduct an electric current, will be compared between various elements.

  Investigation 4: We will focus on the group of elements that are found on the Periodic Table of the Elements between the metals and nonmetals – the metalloids.

  Note: At this point, we wish to simply introduce the terms metal, nonmetal and metalloid to students without discussing the difference between them. Students will develop a feel for these differences in the next several Labs.

  Note: In Investigation 1, students will physically place various elements onto the Periodic Table in the correct place. We wish students to understand the Table is not an abstract concept, but rather a “filing system” for placing elements near each other in order of similar and different properties!

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• Tell students that this final slide
  • highlights the elements they will handle in Investigation 1,
  • shows them where these elements are located on the Periodic Table, and
  • reminds them to wear goggles and gloves.

  Note: While these particular elements are harmless in the form we will be using them, students must nonetheless become accustomed to wearing safety equipment when handling any chemical materials in the Lab.