Chemistry Of Main Group Elementscourse Introduction Topic

Chemistry of Main Group Elements - Course Introduction (Detailed Notes)

1. Classification of Elements:

  • Metals: Elements that readily lose electrons to form positive ions (cations).
    • Alkali metals (Group 1): Highly reactive, form 1+ ions.
    • Alkaline earth metals (Group 2): Less reactive than alkali metals, form 2+ ions.
  • Non-metals: Elements that readily accept electrons to form negative ions (anions).
    • Halogens (Group 17): Highly reactive, form 1- ions.
    • Noble gases (Group 18): Unreactive, form stable monoatomic gases.
  • Metalloids: Elements that have properties of both metals and non-metals.
    • Boron (Group 13), Silicon (Group 14), Germanium (Group 14), Arsenic (Group 15), Antimony (Group 15), Tellurium (Group 16).

2. Periodic Trends (Variations Across the periodic Table):

  • Atomic size and radius: Atomic radius decreases across a period (left to right) and increases down a group (top to bottom).
  • Ionization energy: Ionization energy increases across a period and decreases down a group.
  • Electron affinity: Electron affinity increases across a period and decreases down a group.
  • Electronegativity: Electronegativity increases across a period and decreases down a group.
  • Oxidation states: Oxidation states of elements become more positive across a period and more negative down a group.

3. Structures and Bonding:

  • Ionic bonding: Involves the transfer of electrons from a metal atom to a non-metal atom, resulting in the formation of positively charged cations and negatively charged anions.
  • Covalent bonding: Involves the sharing of electron pairs between atoms, resulting in the formation of molecules.
  • Metallic bonding: Involves the attraction between positively charged metal ions and the sea of mobile electrons in a metal lattice.

4. Nomenclature:

  • Systematic naming of elements and compounds according to their composition and structure.
  • IUPAC (International Union of Pure and Applied Chemistry) guidelines for naming inorganic compounds.

5. Chemical Reactions and Reactivity of Main Group Elements:

  • Reactivity of alkali metals and alkaline earth metals: Highly reactive, readily react with water, oxygen, and halogens.
  • Reactivity of halogens: Highly reactive, readily react with metals, non-metals, and organic compounds.
  • Reactivity of noble gases: Unreactive under normal conditions.
  • Formation and properties of oxides, hydroxides, carbonates, and sulfates: Reactions of main group elements with oxygen, water, and carbon dioxide.

6. Applications and Uses of Main Group Elements:

  • Industrial applications: Catalysts, batteries, semiconductors, glass, cement, fertilizers.
  • Everyday uses: Food preservation, cosmetics, pharmaceuticals, cleaning products, energy storage.

References:

  • NCERT Chemistry, Class 11, Chapter 3: Classification of Elements and Periodicity in Properties
  • NCERT Chemistry, Class 11, Chapter 4: Chemical Bonding and Molecular Structure
  • NCERT Chemistry, Class 12, Chapter 1: The Solid State
  • NCERT Chemistry, Class 12, Chapter 2: Solutions
  • NCERT Chemistry, Class 12, Chapter 3: Electrochemistry
  • NCERT Chemistry, Class 12, Chapter 10: The d- and f- Block Elements