Rock Cycle - Chemistry (2)

  • Comparing characteristics of different elements.
  • Observing the elements on the periodic table.
  • compound
  • elements
  • periodic table

Students evaluate different elements that can be found naturally or synthetically.

Sulfur forming along the rim of this volcano


In our everyday world, we are see and use "elements" in many ways. Advertisements talk about, "Iron is needed for our blood" or "Silicon Valley." Unfortunately, not all references to elements are scientifically accurate. For instance, lead in a pencil is not the element lead, but the mineral graphite which is composed of the element carbon. A five cent nickel only has a small percentage of the metal nickel in it. The calcium in milk is not the element calcium, just a small percentage of calcium is contained in the chemical composition. Elemental calcium is a silver white metal and is very reactive.

The elements are grouped into units that have similar properties. For example elements 2,10,18,36,54, and 86 are classified as "rare or inert gases." Notice also that the colors on the periodic table refer to groups of elements that have similar characteristics. If an element is found naturally not in combination with other elements it is called a native element or native mineral.

Most of the "elements" that we are exposed to in advertising are really combinations of elements (compounds). In this exercise the students will learn the characteristics of certain elements. Please note that some of the items may not be 100% pure, but they still exhibit to students the characteristics of that element in its pure state.

  1. Tell the students that today they will be looking at some of the elements found on the Periodic Table. These elements are either found in nature or manufactured (silicon). As they look at the samples tell them that they will need to use words to describe them.
  2. Practice words that describe something (color, texture, etc.).
  3. Pass out the student lab sheets. As students look at the samples and try to find both the atomic symbol and the atomic number of the element using the periodic table. They will learn in later grades that the atomic numbers refer to the number of protons the element possesses. Ask them to record this information in the appropriate boxes on the lab sheet.
  4. After they complete this, ask them to describe the minerals in descriptive words. Record these in the box on their lab sheet.
  5. As they finish up, orally read the conclusion question. Tell them that the work 'characteristics' in this case means how it looks and feels. Elicit responses as to what the students think might be the answer. Then ask them to write down their response.
  6. Go over some of the properties of each of the elements found in the lab. You may want to help the students develop a descriptive vocabulary before they begin the lab. Below are some accurate descriptions of the lab specimens.

    COPPER - copper color, used to make pipes, teapots, etc (native mineral)
    - gray color, used to make nickels and metal, naturally magnetic
    - gray color, used to make metals, flexible, heavy
    - white or gray color, used in computer industry to make computer chips
    - gray color, used in making pencils, rubs off easily
    - yellow color, used in making medicine, (native mineral)
    - gray color, used to make aluminum foil and other metals
    - gray color, used in the steel industry, and has other uses as a metal
    - gray color, used as metal
    - gray color, shiny, bends, used as a metal

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