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 is the structure formed by oppositely charged ions in ionic bonding?

  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 ionic radius have on the strength of ionic bonding?

  Larger ions have a weaker attraction due to greater distance
• What are cations and anions?

  Cations are positively charged ions and anions are negatively charged ions
• How can ionic bonding be represented visually?

  Using dot and cross diagrams
• What is the main characteristic of covalent bonds?

  They form between two non-metals
• What occurs in covalent bonding regarding electrons?

  Electrons are shared between the two outer shells
• What can multiple electron pairs in covalent bonding produce?

  Multiple covalent bonds
• How are shared electron pairs represented in dot and cross diagrams?

  The overlap includes a covalent bond
• What is a single covalent bond represented by in terms of electrons?

  2 electrons (1 from each atom)
• How does bond length relate to bond strength in covalent bonds?

  Shorter bonds tend to be stronger
• What is a dative bond?

  A bond where 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
• What type of forces hold simple covalent substances 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 the common shapes of molecules based on bonding and lone pairs?

  • 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 a period and down a group in the periodic table?

  Electronegativity increases across 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 is the relationship between electronegativity and polar molecules?

  Polar molecules must have polar bonds, but a molecule with polar bonds may not necessarily be polar
• How does the geometry of a molecule affect its polarity?

  The arrangement of polar bonds and the overall shape determines if the molecule is polar
• What are van der Waals forces?

  The weakest type of intermolecular force, acting as an induced dipole between molecules
• How does the molecular weight (Mr) affect van der Waals forces?

  The greater the Mr of the molecule, the stronger the intermolecular forces
• How does branching in alkane chains affect van der Waals forces?

  Branching weakens van der Waals forces as branched chains cannot pack tightly together
• What is the effect of chain length on the boiling point of alkanes?

  As chain length increases, the boiling point increases due to stronger intermolecular forces
• What happens when two atoms bonded have sufficiently different electronegativities?

  A polar bond forms
• What is the relationship between polar bonds and polar molecules?

  A molecule with polar bonds may not necessarily be a polar molecule
• How does the arrangement of polar bonds affect the overall polarity of a molecule?

  The arrangement can lead to cancellation of dipoles, resulting in a non-polar molecule
• What is the significance of the geometry of water (H₂O) in its polarity?

  The bent geometry leads to an overall polarity due to the arrangement of polar O-H bonds