bonding & structure

• What type of bonding occurs between a metal and a non-metal?

  Ionic bonding
• What happens to electrons during ionic bonding?

  Electrons are transferred from the metal to the non-metal
• What are charged particles formed during ionic bonding called?


  ions
• What do oppositely charged ions form through electrostatic forces?

  A giant ionic lattice
• What ions are formed in sodium chloride?

  Na⁺ and Cl^-
• How does the charge of an ion relate to the strength of the ionic bond?

  Ions with a greater charge have a greater attraction, resulting in stronger ionic bonds
• What effect does a larger ionic radius have on ionic bonding?

  Larger ions have a weaker attraction to oppositely charged ions due to greater distance
• What are cations and anions represented with in dot and cross diagrams?

  Dot and cross diagrams
• What does a dot and cross diagram show in ionic bonding?

  The electrons being transferred from the cation to the anion
• What type of bonding occurs between two non-metals?

  Covalent bonding
• What is formed when electrons are shared between two non-metals?

  A covalent bond
• How many electron pairs can be shared to produce multiple covalent bonds?

  Multiple electron pairs can be shared
• What is the displayed formula for a single covalent bond?

  Single bond is represented as a line
• What is the displayed formula for a double covalent bond?

  Double bond is represented as =
• What is the displayed formula for a triple covalent bond?

  Triple bond is represented as ≡
• How does bond length relate to bond strength?

  Shorter bonds tend to be stronger
• Why are double and triple bonds stronger than single covalent bonds?

  They are shorter, holding atoms closer together
• What forms a dative bond?

  When both electrons in the shared pair are supplied from a single atom
• How is a dative bond indicated in diagrams?

  Using an arrow from the lone electron pair
• What happens to a dative bond once it has formed?

  It is treated as a standard covalent bond
• How are electrons represented in dot and cross diagrams for dative bonds?

  Both electrons will have the same shape (either both dots or both crosses)
• What type of forces hold simple molecular structures together?

  Weak van der Waals forces
• What determines the shape of a simple molecule or ion?

  The number of electron pairs around the central atom and the repulsion between them
• How does the presence of lone pairs affect bond angles?

  Lone pairs provide additional repulsive forces, reducing bond angles by 2.5° for each lone pair
• What are the steps to determine the shape of a molecule?

  1. Find the number of electron pairs.
  2. Determine how many pairs are bonding pairs and how many are lone pairs.
  3. Bonding pairs indicate the basic shape; lone pairs indicate additional repulsion.

  
• What is bond length?

  The average distance between two nuclei in a covalent bond
• What is bond angle?

  The angle between two covalent bonds from the same atom
• What are some common molecule shapes and their characteristics?

  • Linear: 2 bonding pairs, 0 lone pairs, bond angle 180°
  • V-Shaped: 2 bonding pairs, 2 lone pairs, bond angle 104.5°
  • Trigonal Planar: 3 bonding pairs, 0 lone pairs, bond angle 120°
  • Triangular Pyramid: 3 bonding pairs, 1 lone pair, bond angle 107°
  • Tetrahedral: 4 bonding pairs, 0 lone pairs, bond angle 109.5°
  • Trigonal Bipyramidal: 5 bonding pairs, 0 lone pairs, bond angles 90° and 120°
  • Octahedral: 6 bonding pairs, 0 lone pairs, bond angle 90°
• What is electronegativity?

  The power of an atom to attract the electron pair in a covalent bond towards itself
• How does electronegativity change across the periodic table?

  It increases along a period and decreases down a group
• What happens if the electronegativity difference between two atoms is great enough?

  An ionic bond will form between them
• What is a polar bond?

  A bond that results from a large difference in electronegativity between two atoms
• What is the electronegativity difference range for a polar covalent bond?

  Between 0.4 and 1.7
• What happens if the electronegativity difference is greater than 1.7?

  The bond will be ionic
• What is a polar molecule?

  A molecule with an overall difference in polarity due to the arrangement of polar bonds
• Can a molecule with polar bonds be non-polar?

  Yes, if the geometry of the molecule causes the dipoles to cancel out
• What are the three main types of intermolecular forces?

  Van der Waals forces, permanent dipole, and hydrogen bonds
• What are van der Waals forces?

  The weakest type of intermolecular force acting as an induced dipole between molecules
• How does the strength of van der Waals forces vary?

  It varies depending on the molecular mass and shape
• How does chain length affect the boiling point of alkanes?

  As chain length increases, the boiling point increases due to stronger intermolecular forces