U4 - Bonding and Naming

• Covalent bonds - nonmetal and another nonmetal SHARING valence electrons to fulfill octet
• Ionic bond - metal loses electron(s) to form positive ion, non-metal gains electron(s) to form negative ion.
• Polyatomic Ions - Positively charged polyatomics (ammonium only) will replace cations. Negatively charged polyatomics (the others lol) will replace anions.
• Molecular Geometry: 5 Main shapes

  1. Linear
  2. Bent
  3. Trigonal Planar
  4. Trigonal Pyramidal
  5. Tetrahedral
• Bent molecules MUST have at least one lone pair, maximum of two lone pairs.
• VSEPR Theory - the idea electron groups repel one another.

  V - Valence

  S - Shell

  E - Electrons

  P - Pair

  R - Repulsion

  Electron pairs spread apart as far as possible. Lone pairs take up space around the atom.
• Why do molecules have different bonding angles?

  The arrangement of atoms around a central atom affects the bonding angles of a molecule. According to the VSEPR theory, electrons want to be as far away from each other as possible. This causes atoms to arrange themselves to be as far apart as possible, with equal distance/angles in between. The more atoms there are, the smaller the bond angle gets. Lone pairs also take up space around the atom, causing bonding angles to decrease as well.
• Electron groups:

  • Lone pairs * *
  • Single Bonds -
  • Double bonds =
  • Triple Bonds ☰
• Transition metals with set charges:

  • Aluminum (+3)
  • Zinc (+2)
  • Cadmium (3)
  • Silver (+1)

  With these four transition metals, roman numerals are not necessary
• Show electron transfer for normal ionic bonding
• What is the chemical formula for barium bromide?

  BaBr2