C2-Bonding, Structure and Properties of matter

• What is an ion?

  Charged particles made when electrons are transferred.
• How are positive ions formed?

  By losing electrons.
• What charge do metals typically form when they become ions?

  1+ charge.
• How are negative ions formed?

  By gaining electrons.
• What charge do non-metals typically form when they become ions?

  1. or 1- charge.
• What is ionic bonding?

  The electrostatic attraction between oppositely charged ions.
• Between which types of ions does ionic bonding occur?

  Between positive metal ions and negative non-metal ions.
• What is the formula for sodium chloride?

  NaCl
• What do dot-cross diagrams represent?

  The transfer of electrons in ionic bonding.
• What is a limitation of dot-cross diagrams?

  They don’t show compound structure or the size and arrangement of ions.
• Why do ionic compounds have high melting and boiling points?

  Because lots of energy is needed to overcome the many strong bonds.
• When can ionic compounds conduct electricity?

  Only when molten or dissolved.
• What are the three properties of ionic compounds?

  1. Giant ionic lattice structure with electrostatic forces of attraction.
  2. High melting and boiling points due to strong bonds.
  3. Conduct electricity only when molten or dissolved.
• What is a covalent bond?

  A shared pair of electrons between two non-metal atoms.
• In which types of compounds does covalent bonding occur?

  In non-metal compounds and non-metal elements.
• What is a limitation of dot and cross diagrams in covalent bonding?

  They don't show relative sizes of atoms or their arrangement in space.
• What do molecular formulas show?

  How many atoms of each element are in a compound.
• What do ball and stick diagrams fail to show?

  Which atoms the electrons in the bonds come from.
• What is the difference between covalent bonds and forces between molecules?

  Covalent bonds are strong, while forces between molecules are weak.
• What are two properties of simple molecular substances?

  1. Low melting and boiling points; mostly gases or liquids at room temperature.
  2. Don't conduct electricity; there are no charged particles to carry charge.
• Why are polymers usually solid at room temperature?

  Because they have relatively strong intermolecular forces.
• What are polymers?

  Very long chains of repeating units.
• What are giant covalent structures?

  • Solids containing atoms bonded by strong covalent bonds.
  • High melting and boiling points due to strong bonds.
  • Don't conduct electricity (with a couple of exceptions).
• What is an example of a giant covalent structure?

  Diamond
• What is the melting point of giant covalent structures?

  High, due to lots of energy needed to overcome strong covalent bonds.
• What is the structure of diamond?

  Carbon atoms form four covalent bonds.
• What is the conductivity of graphite?

  Conducts electricity and thermal energy.
• Why do giant covalent structures not conduct electricity?

  Because there are no charged particles to carry charge.
• What is the structure of graphite?

  Carbon atoms form three covalent bonds.
• What are fullerenes?

  Hollow shapes made of carbon atoms.
• Why is graphite soft and slippery?

  Because there are no covalent bonds between layers.
• What is Buckminsterfullerene?

  A spherical fullerene that was the first to be discovered.
• What are nanotubes used for?

  Used in nanotechnology, electronics, and materials.
• What is metallic bonding?

  Metal atoms held together by strong electrostatic attraction.
• Why are alloys harder than pure metals?

  Because they distort layers of metal atoms, preventing them from sliding past each other.
• What is the particle arrangement in solids?

  Regular and fixed position, vibrating.
• What are the four properties of metals?

  1. High melting and boiling points.
  2. Good thermal conductors.
  3. Good electrical conductors.
  4. Soft and malleable.
• What is the particle arrangement in gases?

  Random and moving quickly in all directions.
• What is the particle arrangement in liquids?

  Close together, moving around each other.
• What happens to particles during melting?

  Forces between particles weaken, allowing them to break free from position.