Covalent Bonding & Structure

• What type of interaction allows atoms to share electrons?

  Covalent bonding
• What kind of attraction is a covalent bond?

  Strong electrostatic attraction
• What is formed between a shared pair of electrons and the nuclei of the bonded atoms?

  A covalent bond
• What does covalent bonding create?

  A stable molecule
• What is a stable molecule?

  A group of atoms held by covalent bonds
• What determines the strength of a covalent bond?

  The energy needed to break the bond
• What value is used to measure the strength of a covalent bond?

  Average bond enthalpy
• In what units is average bond enthalpy expressed?

  kJ mol-1
• What does a higher average bond enthalpy value indicate?

  A stronger covalent bond
• What is the average bond energy of a N≡N triple bond?

  945 kJ mol-1
• What does the high bond energy of N≡N indicate?

  It is a very strong bond
• What is the average bond energy of a F-F single bond?

  159 kJ mol-1
• What does the lower bond energy of F-F indicate?

  It is a weaker bond
• What determines the number of covalent bonds an atom forms?

  Electrons needed to fill its outer shell
• What can atoms share to fill their outer shell?

  Multiple electron pairs
• What type of bonds are formed when atoms share multiple electron pairs?

  Double or triple bonds
• How many electrons does oxygen need to complete its outer shell?

  2
• How does oxygen form a double bond?

  By sharing 2 sets of electrons
• How many electrons does nitrogen need to complete its outer shell?

  3
• How does nitrogen form a triple bond?

  By sharing 3 sets of electrons
• What is another name for dative covalent bonding?

  Coordinate bonding
• In dative covalent bonding, where do both shared electrons come from?

  Just one of the bonding atoms
• What is the first requirement for a dative covalent bond to form?

  One atom must have a lone pair
• What is the second requirement for a dative covalent bond to form?

  The other atom must be electron deficient
• How is dative covalent bonding represented?

  By an arrow
• What do covalent bonds do within a molecule?

  Hold atoms together
• What force holds the covalent bond together?

  Electrostatic attraction
• What does the arrow in dative covalent bonding show?

  Direction of electron donation
• What type of structure is formed by elements that can form extensive interconnecting networks of covalently bonded atoms?

  Giant covalent structures
• What is the dimensionality of the lattices in giant covalent structures?

  Three dimensions
• What two properties of carbon allow it to form giant covalent structures?

  Small atomic size and ability to form 4 bonds
• What term describes different structural forms of an element in the same state?

  Allotropes
• What are the three allotropes of carbon with giant lattice structures mentioned?

  Diamond, graphite, and graphene
• In diamond, how many covalent bonds does each carbon atom form?

  Four
• What is the arrangement of carbon atoms in diamond?

  Tetrahedral
• Why is diamond extremely hard?

  Extensive network of strong covalent bonds
• Why does diamond have a very high melting point?

  Huge energy needed to break many bonds
• Why is diamond a good thermal conductor?

  Strong bonds transmit heat through vibrations
• Why is diamond an electrical insulator?

  All outer electrons are tied up
• Why is diamond insoluble?

  Covalent bonds too strong to be broken