Chemical compounds and bonding

• Ionic compounds: Substance made of a cations and anions in a fixed ratio
• Molecular compound: Substance made of non-metal elements in covalent bonds
• Electrolyte: Compound that can conduct electricity when disassociated in water
• Ions are arranged in a crystal lattice structure

  • Each ion+ surrounded by 6 ions-, vice versa
• Ionic compound properties:

  1. High melting point (high energy to break bonds)
  2. Great electrical conductors in aqueous and liquid states
  3. Hard and brittle
• Why are element part of HOFBrINCl?

  Molecular elements: Form covalent bond with atoms of the same element, to become stable
• Molecular compound properties:

  1. Low melting points (Not much energy to break bonds)
  2. Poor electrical conductors (Neutral molecules)
  3. Soft and malleable
  4. Exist as gases, solids, or liquids
• Expanded octet: Elements which can share more than 8 electrons in covalent bonds to become stable.

  • Non-metal elements period 3 and below
• Electronegativity: The ability for an atom to attract its bonding electrons to its nucleus.
• Bonding Continuum: Used to determine the polarity of a chemical bond
• Differences in electronegativity:

  • 0 - 0.4 --> Non-polar covalent
  • 0.5 - 1.6 --> Polar covalent
  • 1.7 - 3.0 --> IONIC
• Polar molecules: Slightly charged ends (unsymmetrical, imbalance of forces)
• Non-polar molecules: Overall neutral (Symmetrical and forces "cancel" each other)
• Bonding Capacity - The # of covalent bonds an atom need to become stable
• How is bonding capacity related to valence electrons?

  Valence electrons tell us how many electrons the element needs to achieve full valance