structures

• How does particle theory explain changes in state like melting and boiling?

  It relates to energy and particle forces.
• What determines the amount of energy needed to change state?

  The strength of forces between particles.
• What does the nature of the particles depend on?

  The type of bonding and structure.
• How do melting and boiling points relate to particle forces?

  Stronger forces lead to higher melting and boiling points.
• What are the limitations of the simple particle model?

  It lacks forces and represents particles as solid spheres.
• What are the state symbols for solid, liquid, gas, and aqueous solutions?

  (s), (l), (g), and (aq)
• What structure do ionic compounds have?

  Giant ionic lattices with strong electrostatic forces.
• Why do ionic compounds have high melting and boiling points?

  Because a lot of energy is needed to break strong bonds.
• Why can ionic compounds conduct electricity when melted or dissolved?

  Because ions are free to move and carry current.
• Why can't ionic compounds conduct electricity when solid?

  Because the ions are fixed in place.
• What states of matter do small molecules usually exist in?

  Gases or liquids with low boiling points.
• What type of forces exist between small molecules?

  Weak intermolecular forces.
• How do intermolecular forces affect the boiling and melting points of small molecules?

  Larger molecules have higher melting and boiling points.
• Why don't small molecules conduct electricity?

  They do not have an overall electric charge.
• What characterizes polymers in terms of molecular size?

  They have very large molecules.
• How are atoms in polymer molecules linked?

  By strong covalent bonds.
• Why are polymers solids at room temperature?

  Because of relatively strong intermolecular forces.
• What are giant covalent structures characterized by?

  Very high melting points and strong covalent bonds.
• What must be overcome to melt or boil giant covalent structures?

  Strong covalent bonds between atoms.
• What type of bonding do metals have?

  Strong metallic bonding in giant structures.
• Why do most metals have high melting and boiling points?

  Due to strong metallic bonds in their structure.
• How do the layers of atoms in metals behave?

  They can slide over each other, allowing shaping.
• What are alloys made from?

  Two or more different types of metals.
• How do different sized atoms in alloys affect their properties?

  They distort layers, making alloys harder.
• Why are metals good conductors of electricity?

  Delocalised electrons carry electrical charge.
• How do delocalised electrons contribute to thermal conductivity in metals?

  They transfer energy through the metal.