Lecture on the Periodic Table of Elements

Structure of the Periodic Table

• Columns: Called groups
  • Group 1: Alkali Metals
  • Group 2: Alkaline Earth Metals
  • Groups 3-12: Transition Metals
  • Group 16: Calcagens
  • Group 17: Halogens
  • Group 18: Noble Gases
• Rows: Called periods
• Special Series:
  • Lanthanides (after Barium, element 57)
  • Actinides (after Radium, element 88)

Properties of Groups

• Alkali Metals (Group 1):
  • Include lithium, sodium, potassium, rubidium, cesium, francium
  • Highly reactive, especially with water (increases down the group)
  • Low melting points, low density (float on water)
• Alkaline Earth Metals (Group 2):
  • Include beryllium, magnesium, calcium, strontium, barium, radium
  • Reactive but less so than alkali metals
• Transition Metals:
  • Multiple oxidation states (e.g., iron can be +2 or +3, copper can be +1 or +2)
• Halogens (Group 17):
  • Include fluorine, chlorine, bromine, iodine
  • Non-metals, similar chemical reactivity
• Noble Gases (Group 18):
  • Include helium, neon, argon, krypton, xenon, radon
  • Chemically inert, do not readily form compounds

Valence Electrons and Ion Formation

• Group number can denote valence electrons:
  • Group 1 (1a) has 1 valence electron
  • Group 2 (2a) has 2 valence electrons, and so on.
• Cations and Anions:
  • Metals (left side of table) tend to lose electrons to form cations (positive ions)
  • Non-metals (right side) gain electrons to form anions (negative ions)

Metals, Non-metals, and Metalloids

• Metals:
  • Conduct electricity and heat
  • Malleable and ductile
  • Form cations
• Non-metals:
  • Poor conductors, brittle
  • Form anions
• Metalloids:
  • Exhibit properties of both metals and non-metals
  • Semiconductors (e.g., silicon, germanium)
  • Conductivity increases with temperature

Atomic Structure

• Atomic Number: Equals number of protons
• Atomic Mass: Average atomic mass of element
• Isotopes: Forms of an element with different numbers of neutrons (e.g., carbon-12, carbon-13, carbon-14)

Common Elements and Uses

• Hydrogen (H): Fuel for stars
• Helium (He): Used in balloons
• Lithium (Li): Lithium-ion batteries
• Sodium (Na): Found in table salt
• Potassium (K): High in bananas
• Iron (Fe): Important metal with industrial uses
• Copper (Cu) and Silver (Ag): Used in electrical wiring
• Gold (Au) and Platinum (Pt): Valuable metals

Miscellaneous Notes

• Learn symbols and names for quizzes (e.g., Li for lithium, Be for beryllium)
• Diatomic Elements:
  • Nitrogen (N2), Oxygen (O2), Fluorine (F2), Chlorine (Cl2), Bromine (Br2), Iodine (I2)
• Safety Note: Radon is radioactive and can accumulate in homes

Ensure to memorize the common elements and their symbols, their properties, and the group characteristics for a solid understanding of the periodic table dynamics.