Periodic Table Overview

Classification of Elements

• Groups:

  • Vertical columns on the periodic table.
  • Elements in the same group have similar chemical properties.
  • Numbered 1-18 or alternatively 1A-8A for certain groups to consider valence electrons.

• Periods:

  • Horizontal rows on the periodic table.
  • Numbered 1-7.

Types of Elements

Metals

• Alkali Metals (Group 1 or 1A):

  • Soft, silvery, extremely reactive.
  • Examples: Lithium, Sodium, Potassium.
  • React with water; found in nature only in combination with other elements.

• Alkaline Earth Metals (Group 2 or 2A):

  • Reactive, but less than alkali metals.
  • Examples: Magnesium, Calcium, Strontium.
  • Not found in pure state in nature.

• Transition Metals (Groups 3-12):

  • Generally metals with similar properties.

• General Properties of Metals:

  • Solid at room temperature (except Mercury).
  • Malleable and ductile.
  • Good conductors of heat and electricity.

Nonmetals

• Halogens (Group 7A or 17):

  • Very reactive nonmetals; often colorful and corrosive.
  • Known as salt formers.
  • Examples: Fluorine, Chlorine, Bromine.

• Noble Gases (Group 8A or 18):

  • Colorless, generally unreactive gases.
  • Examples: Helium, Neon, Argon.

• General Properties of Nonmetals:

  • Solids tend to be brittle.
  • Poor conductors of heat and electricity.

Metalloids

• Elements with properties intermediate between metals and nonmetals.
• Found along the zigzag line on the periodic table.
• Examples: Boron, Silicon, Germanium, Arsenic.
• Silicon is a well-known semiconductor.

Organization of the Periodic Table

• Metals are primarily located on the left side.
• Nonmetals are on the right side.
• The zigzag line separates metals and nonmetals, with metalloids along this line.

Next Steps

• Future discussions will include electronic structure and the definition of transition metals.