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Science Dept.

Chemistry CHE 100 Notes
G. The Periodic Table of the Chemical Elements

1. Some History
   1. Lothar Meyer (1830-1895) in 1864 first proposed a table of the Chemical Elements

   2. Dimitri Mendeleev (1834-1907) in 1869 proposed a more complete table of the Chemical Elements

   3. Mendeleev listed the elements in order of increasing Atomic Weight (or Mass) from Left to Right
      1. Except for the problem of Ar and K the listing from L or R works well

      2. Henry Moseley solved this problem when he "discovered" the Z number, which is the Atomic Number

      3. Today we list the elements in order of increasing Atomic Number from L to R, and we know that the chemical properties of these elements are due to their Atomic Number

      4. Mendeleev noticed that the elements showed a recurrent periodicity (from metal to nometal)

      5. Stack these periods on top of one another. Do you see the Group or Family relationships?

   4. Julius Thomsen is responsible for the long form of the Periodic Table of the Elements

2. Periods
   1. A Period is a Horizontal Row in the Table of Elements

   2. There are Seven Major Periods or Horizontal Rows

   3. H to He, Li to Ne, Na to Ar, K to Kr, Rb to Xe, Cs to Rn, and the seventh, starting with Fr is not complete

   4. The Atomic Radii Decrease from L to R in any Period

   5. The Ionic Radii Increase from L to R in any Period

   6. Metallic Properties Decrease from L to R in any Period

3. Groups or Families
   1. A Group or Family is a Vertical Column in the Table of Elements

   2. A Family of Elements has similar chemical characteristics due to similar electronic configurations of the outermost electrons

   3. The Atomic Radii Increases downward in any Group

   4. The Metallic properties Increase downward in any Group

   5. Names
      1. Group IA is called the Alkali Metals
      2. Group IIA is called the Alkali Earth Metals
      3. Group B elements are called Transition Elements
      4. Group IIIA is called the Aluminum Family
      5. Group IVA is called the Carbon Family
      6. Group VA is called the Nitrogen Family
      7. Group VIA is called the Oxygen or Sulfur Family
      8. Group VIIA is called the Halogens
      9. Group VIIIA is called the Inert or Noble Gases

4. Use of the Periodic Table of the Elements
   1. Predict Compound Formula
      1. What is the formula for Carbon Dioxide?

      2. What is the formula for Potassium Fluoride?

      3. What is the formula for Aluminum Bromide?

   2. Predict Bond (Ionic or Covalent) Type
      1. What is bond type of NaCl?

      2. What is bond type of SO₂?

      3. What is bond type of H₂?

   3. Predict Some Oxidation States
      1. What is the Oxidation State of Na?

      2. What is the Oxidation State of Ca?

      3. What is the Oxidation State of Al?

      4. What is the Oxidation State of Cl?

5. How About a Quick Quiz?

6. How About Another Quick Quiz?