Properties of covalent structures

• 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
• Name two examples of simple molecular substances.

  Chlorine and ammonia
• What are giant covalent structures made of?

  Huge numbers of non-metal atoms
• Give three examples of giant covalent structures.

  Diamond, graphite, silicon dioxide
• What is a key property of covalent bonds?

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

  Break 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 is the boiling point of iodine?

  184 degrees Celsius
• Why don't simple molecular substances conduct electricity?

  They have no free electrons
• What is a characteristic of giant covalent structures regarding their melting and boiling points?

  They have high melting and boiling points
• Why don't giant covalent structures conduct electricity?

  They lack charged particles
• What is the composition ratio of silicon dioxide?

  1 silicon to 2 oxygen
• What is silicon dioxide also known as?

  Silica
• 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
• How do the properties of diamond and graphite differ from silicon dioxide?

  Diamond and graphite conduct electricity; silicon dioxide does not
• What is the structure of giant covalent structures like?

  Regular repeating lattices
• What is the main takeaway from the video about molecular substances?

  Simple molecules have weak intermolecular forces