Bonding

• What type of bond is formed between a non-metal and a metal?

  Ionic bond
• What is the main characteristic of a covalent bond?


  It involves the sharing of electrons between non-metals
• How is a covalent bond defined in terms of electrostatic attraction?


  It is the attraction between shared electrons and the positive nuclei of atoms
• What is required to break strong covalent bonds?


  More energy is required to break strong attractions
• What state are ionic compounds typically found in at room temperature?


  Solid state
• What is a giant ionic lattice?


  It is a large regular structure of ionic compounds
• Why can't ionic compounds conduct electricity in solid state?


  Because ions are closely packed and cannot move
• When can ionic compounds conduct electricity?


  In molten and solution states when ions are free to move
• What holds the structure of a giant ionic lattice together?


  Electrostatic attraction between oppositely charged ions
• What happens to metal atoms during ionic bonding?


  They lose electrons to become positively charged ions
• What happens to non-metal atoms during ionic bonding?


  They gain electrons to become negatively charged ions
• What are the characteristics of giant covalent structures like diamond?


  • Each carbon atom forms 4 strong covalent bonds
  • Cannot conduct electricity (no delocalised electrons)
  • High melting and boiling points due to strong covalent bonds
• Why does diamond have high melting and boiling points?

  Due to the large number of strong covalent bonds that require more energy to break
• What are the properties of simple molecular structures?

  • Weak intermolecular forces
  • Typically liquids or gases at room temperature
  • Low melting and boiling points
  • Insoluble in water
  • Cannot conduct electricity in any state
• What are the properties of graphite?


  It has 3 covalent bonds per carbon atom and can conduct electricity due to delocalised electrons
• Why is graphite soft and slippery?


  Due to weak intermolecular forces between layers allowing them to slide
• What is the structure of fullerene?


  A group of spherical carbon molecules with hexagonal rings
• What is unique about C60, also known as Buckminster fullerene?


  It has delocalised electrons but cannot move from one molecule to another
• What are the properties of carbon nanotubes?


  • Cylindrical structure with high length to diameter ratio
  • High surface area to volume ratio
  • Strong and lightweight
• What is graphene?


  A single layer of graphite with strong covalent bonds
• What is metallic bonding?


  It is the electrostatic attraction between positive metal ions and delocalised electrons
• What are the characteristics of metallic structures?


  • Positive ions in a regular pattern
  • Delocalised electrons that can move
  • Malleable and ductile
  • Good conductors of heat and electricity
  • High melting and boiling points
• What happens to the layers of positive ions in metallic structures?


  They can slide over each other
• What is an alloy?


  A mixture of two or more different elements, at least one being a metal
• Why are alloys harder than pure metals?


  Different sized atoms distort the layers, making it harder for them to slide