Covalent bonding

• What is covalent bonding?

  • Involves sharing of outer electrons
  • Electrostatic attraction between shared electrons and positive nucleus
  • Can form single, double, and triple bonds
• What is a dative covalent bond?

  A bond where one atom donates a pair of electrons to another atom
• How is a dative covalent bond represented in diagrams?

  With an arrow showing the direction of electron donation
• What are the characteristics of giant covalent structures like graphite and diamond?

  • High melting points
  • Strong covalent bonds
  • Graphite conducts electricity; diamond does not
  • Graphite has layers that can slide; diamond is hard
• What is the structure of graphite?

  Made up of hexagons with delocalized electrons
• Why does graphite conduct electricity?

  Due to delocalized electrons that can carry a charge
• How does diamond differ from graphite in terms of bonding?

  Each carbon in diamond is bonded four times, while in graphite it is bonded three times
• What is the melting point characteristic of diamond?

  Very high melting point
• Why is diamond non-conductive of electricity?

  It does not have free electrons
• What is covalent bonding?

  Covalent bonding is the sharing of outer electrons between atoms.
• What types of covalent bonds can be formed?

  Single, double, and triple bonds.
• What is a coordinate bond?

  A coordinate bond is formed when one atom donates both electrons to another atom.
• How is ammonia formed using a coordinate bond?

  Ammonia is formed when nitrogen donates a pair of electrons to hydrogen.
• What is the structure of graphite?

  Graphite is made up of hexagons with delocalized electrons allowing it to conduct electricity.
• Why does diamond have a high melting point?

  Diamond has a high melting point due to strong covalent bonds that require a lot of energy to break.
• Why does graphite conduct electricity while diamond does not?

  Graphite conducts electricity due to delocalized electrons, while diamond does not have free electrons.
• What is the role of delocalized electrons in graphite?

  Delocalized electrons allow graphite to conduct electricity.
• What is the structure of diamond compared to graphite?

  Diamond has a tetrahedral structure with each carbon bonded four times, while graphite has a planar hexagonal structure.
• Why is it important to understand the differences between ionic and covalent bonding?

  Understanding the differences helps predict the properties and behaviors of different compounds.
• What is a co-ordinate bond?

  A co-ordinate (dative covalent) bond contains a shared pair of electrons with both electrons supplied by one atom.
• What defines a covalent bond?

  A covalent bond is a shared pair of electrons between two non-metals.
• What is a lattice in chemistry?

  A lattice is a repeating regular arrangement of atoms, ions, or molecules that occurs in crystal structures.
• What is a macromolecular crystal structure?

  A macromolecular crystal structure consists of giant covalent structures with very high melting points due to many strong covalent bonds that must be broken.
• Can you give examples of macromolecular structures?

  Examples of macromolecular structures include diamond and graphite.
• What characterizes a simple molecular crystal structure?

  A simple molecular crystal structure consists of atoms joined by strong covalent bonds, but weak intermolecular forces result in low melting and boiling points.
• What type of elements do covalent bonds form between?

  Two non-metals
• How are electrons involved in covalent bonding?

  Electrons are shared between the two outer shells
• What can be represented using dot and cross diagrams?

  Shared electron pairs in covalent bonds
• What is a dative bond?

  A bond where both electrons in the shared pair are supplied from a single atom
• What is indicated by an arrow in a dative bond?


  The direction from the lone electron pair to the atom receiving the pair
• What happens to a dative bond once it has formed?

  It is treated as a standard covalent bond
• What are the physical properties of a substance influenced by?

  • Type of bonding
  • Crystal structure