Properties of Simple Molecular Substances,Giant Covalent

• What type of bond do non-metals form by sharing electrons?

  Covalent bonds
• What is the result of non-metals forming covalent bonds?

  Atoms have full outer shells
• What are small molecules formed by non-metals called?

  Simple molecular substances
• What is a key property of covalent bonds?

  They are very strong
• What must be broken to melt or boil chlorine?

  Weak intermolecular forces
• At what temperature does chlorine boil?

  -34 degrees Celsius
• How do intermolecular forces affect boiling points?

  More forces increase boiling points
• What is the boiling point of bromine?

  59 degrees Celsius
• What happens to boiling points as you go down the group of halogens?

  Boiling points increase
• Why don't simple molecular substances conduct electricity?

  They have no free electrons
• What is the structure of giant covalent structures like?

  Regular repeating lattices
• Why do giant covalent structures have high melting and boiling points?

  Strong covalent bonds need breaking
• What is the exception to the conductivity rule for giant covalent structures?

  Graphite conducts electricity
• What is silicon dioxide also known as?

  Silica
• What is the ratio of silicon to oxygen atoms in silicon dioxide?

  1 to 2
• What is the main component of sand?

  Silicon dioxide
• What are the key differences between simple molecular substances and giant covalent structures?

  • Simple molecular substances:
  • Small molecules
  • Weak intermolecular forces
  • Low melting and boiling points
  • Do not conduct electricity

  
  

  • Giant covalent structures:
  • Large networks of atoms
  • Strong covalent bonds
  • High melting and boiling points
  • Generally do not conduct electricity (except graphite)
• What is the key takeaway about simple molecular substances?

  They are small molecules with weak forces
• What is the key takeaway about giant covalent structures?

  All atoms are covalently bonded strongly