Bonding, Structure, and Properties of Matter

• Chemical Bonds


  The forces holding atoms together in compounds
• Types of Chemical Bonds


  • Ionic Bonds
  • Covalent Bonds
  • Metallic Bonds
• Ionic Bonds


  Formed by the transfer of electrons between metals and non-metals
• Covalent Bonds


  Formed by the sharing of electrons between non-metal atoms
• Metallic Bonds


  Formed by the attraction between free-floating valence electrons and positively charged metal ions
• Ionic Bonding


  1. Involves the transfer of electrons from a metal to a non-metal

  2. Results in the formation of positive (cations) and negative ions (anions)

  3. These oppositely charged ions attract each other to form a strong ionic bond
• Ionic Compounds


  • Consist of a lattice structure of repeating positive and negative ions
  • High melting and boiling points due to strong electrostatic forces
  • Conduct electricity when melted or dissolved in water because ions are free to move
• Covalent Bonding


  • Involves the sharing of electron pairs between atoms
  • Each shared pair constitutes one covalent bond
  • Common in organic compounds and molecules like H₂, O₂, and CO₂
• Metallic Bonding


  • Involves the attraction between a lattice of positive metal ions and a 'sea' of delocalized electrons
  • Accounts for properties like conductivity, malleability, and ductility
• Three States of Matter

  • Solids
  • Liquids
  • Gases
• Solids


  Fixed shape and volume, particles tightly packed and only vibrate in place
• Liquids


  Fixed volume but no fixed shape, particles are close but can move past each other
• Gases


  No fixed shape or volume, particles are far apart and move freely
• State Symbols


  • (s)
  • (l)
  • (g)
  • (aq)
• Properties of Ionic Compounds

  • High melting and boiling points
  • Generally soluble in water
  • Conduct electricity when melted or dissolved due to free-moving ions
• Properties of Small Molecules

  • Low melting and boiling points due to weak intermolecular forces
  • Generally do not conduct electricity
  • Many are gases or liquids at room temperature
• Polymers


  • Large molecules made from repeating units (monomers)
  • Properties depend on the type of monomers and the structure of the polymer chains
  • Examples include plastics like polyethylene and biological polymers like DNA
• Giant Covalent Structures


  • Large networks of covalently bonded atoms
  • High melting and boiling points
  • Examples: Diamond (carbon atoms), silicon dioxide (silicon and oxygen atoms)
• Properties of Metals and Alloys

  • Metals are malleable, ductile, and good conductors of heat and electricity
  • Alloys are mixtures of two or more elements, where at least one is a metal
  • Alloys are often stronger and more resistant to corrosion than pure metals
• Metals as Conductors


  Good conductors of electricity and heat due to delocalized electrons that can move freely through the lattice
• Diamond


  • Each carbon atom is bonded to four other carbon atoms in a tetrahedral structure
  • Extremely hard, high melting point, does not conduct electricity
• Graphite


  • Each carbon atom bonded to three others, forming layers of hexagonal rings
  • Layers held together by weak van der Waals forces, allowing them to slide over each other
  • Conducts electricity due to free-moving electrons within layers
• Graphene


  • Single layer of carbon atoms arranged in a hexagonal lattice
  • Excellent conductor, very strong, and flexible
• Fullerenes


  • Molecules of carbon shaped like hollow balls or tubes
  • Used in drug delivery, lubricants, and as catalysts
• Nanoparticles


  • 1-100 nanometers
  • Unique properties due to high surface area to volume ratio
• Microparticles


  Larger than nanoparticles, but still small enough to have different properties compared to bulk material
• Uses of Nanoparticles


  • Medicine: Targeted drug delivery, imaging, and diagnostics
  • Electronics: High-performance semiconductors and displays
  • Catalysts: Enhanced catalytic activity due to large surface area
  • Materials: Stronger, lighter materials with improved properties (e.g., carbon nanotubes)