Covalent Bonding

• What is a molecule?

  A group of two or more atoms bonded together
• What does a molecule represent in chemistry?

  The smallest fundamental unit of a chemical compound
• How are molecules formed?

  Atoms share electrons through covalent bonds
• What is the purpose of shared electrons in a molecule?

  To attain a stable electron configuration
• How many covalent bonds are formed in a water molecule?

  Two covalent bonds
• Between which types of elements does covalent bonding occur?

  Between two non-metals
• What is the nature of the attraction in covalent bonding?

  Electrostatic attraction between nuclei and bonding electrons
• How are electrons involved in covalent bonding?

  Electrons are shared rather than transferred
• What types of covalent bonds can form?

  Single, double, or triple bonds
• What is a single covalent bond?

  Sharing of one pair of electrons between two atoms
• How many electrons are involved in a double covalent bond?

  Four electrons (two pairs)
• What is a triple covalent bond?

  Sharing of three pairs of electrons between two atoms
• How many electrons are involved in a triple covalent bond?

  Six electrons
• What are examples of simple molecular substances?

  • Water (H₂O)
  • Carbon dioxide (CO₂)
  • Methane (CH₄)
• What is simple molecular bonding?

  Formation of discrete molecules through shared electron pairs
• What are the physical properties of simple molecular substances?

  Low melting and boiling points
• Why do simple molecular substances have low melting and boiling points?

  Weak intermolecular forces compared to covalent bonds
• Why are simple molecular substances poor conductors of electricity?

  They lack free electrons or ions
• What is the structure of methane (CH₄)?

  One carbon atom with four hydrogen atoms
• What characterizes giant covalent structures?

  A vast network of atoms bonded by strong covalent bonds
• How do giant covalent structures differ from simple molecular substances?

  They extend in three dimensions throughout the material
• What are the melting and boiling points of giant covalent structures?

  High melting and boiling points
• Why do giant covalent structures have high melting and boiling points?

  Strong covalent bonds require significant energy to break
• What is the hardness of giant covalent structures?

  They are very hard due to strong bonds
• What is an example of a giant covalent structure?

  Diamond
• Why do most giant covalent structures not conduct electricity?

  Lack free-moving charged particles
• What is the exception among giant covalent structures that can conduct electricity?

  Graphite
• Why can graphite conduct electricity?

  It has free electrons that can move
• What holds the layers of graphite together?

  Weak van der Waals forces
• What is the result of the weak forces in graphite?

  Layers can slide over each other, making it slippery
• What is dative covalent bonding?

  Both electrons in a shared pair come from one atom
• What is another name for dative covalent bonding?

  Coordinate bonding
• What does the donor atom do in dative covalent bonding?

  Donates both electrons to the bond
• What must the donor atom have for dative covalent bonding?

  A lone pair of electrons available for donation
• How is a dative covalent bond represented?

  By an arrow pointing from donor to acceptor
• How does a dative covalent bond compare to a regular covalent bond?

  Indistinguishable in strength and length once formed
• What forms the ammonium ion (NH₄⁺)?

  Ammonia donates a lone pair to a hydrogen ion
• What are the characteristics of diamond's structure?

  • Each carbon forms four strong covalent bonds
  • Tetrahedral arrangement
  • Very rigid and strong three-dimensional structure
  • Exceptional hardness and high melting point
• What are the characteristics of graphite's structure?

  • Each carbon forms three covalent bonds
  • Flat, hexagonal layers
  • Fourth electron is free to move
  • Good conductor of electricity
  • Layers held by weak van der Waals forces
  • Soft and slippery