Types of Bonding

A chemical bond is an attraction between atoms that holds them together in space. Atoms bond to achieve a more stable state. Bonds are formed between neighboring atoms by sharing or transferring electrons.

Types of bonding:

• Ionic
  • Electrons are transferred from one atom to another
  • Made up of non-metal and metal atoms
  • Soluble, Conductible when dissolved
  • Usually brittle solids
    • eg. salts (sodium/potassium/etc. chloride)
• Molecular Covalent
  • Valence electrons are shared between pairs or groups of atoms, creating small stable units
  • Made entirely of non-metal atoms
  • Soluble (some), Non-Conductible
  • Mostly liquids and gases
    • eg. water (hydrogen oxide)
• Network Covalent
  • Valence electrons are shared between the entire substance
  • Made entirely of non-metal atoms
  • Non-Soluble, Non-Conductible
  • Extremely hard solids
    • eg. sand (silicon dioxide)
• Metallic
  • Valence electrons move freely about the substance
  • Made entirely of metal atoms
  • Non-soluble, Conductible
  • Bendable, Malleable Solids
    • eg. tin, gold, aluminum

The HONC Rule:

• Hydrogen makes 1 bond
• Oxygen makes 2 bonds
• Nitrogen makes 3 bonds
• Carbon makes 4 bonds

Lewis Dot Structures

• Sh​​​​ows pairs of electrons, both bonded pairs and lone pairs
  • lone pair- a pair of electrons not involved in bonding
• Atoms tend to follow the Octet Rule, except for Hydrogen, which follows the duet rule
  • The number of dots correlates with the number of valence electrons
• Double and Triple bonds
  • Single bond- shares 2 electrons
  • Double bond- shares 4 electrons
  • Triple bond- shares 6 electrons

Electronegativity:

• Electronegativity- the tendency of an atom to attract shared electrons
  • Metals- electron givers; lower electronegativity
  • Non-Metals- electron takers; higher electronegativity
  • Electronegativity increases from right to left across a period and up a group
  • The difference between electronegativities determines how polar a molecule is