bonding, structure and the properties of matter

• What ionic bonding?

  Ionic bonding is the electrostatic attraction between positive and negative ions.

  
  

  It is relatively strong attraction

  
• How are ionic compound

  They are held together in a giant lattice

  It's a regular structure that extends in all directions in a substance

  Electrostatic attraction between positive and negative ions holds the structure together
• State properties of ionic substances

  ● High melting and boiling point (strong electrostatic forces between

  oppositely charged ions)

  ● Do not conduct electricity when solid (ions in fixed positions).

  ● Conduct when molten or dissolved in water - ions are free to move.
• What is a covalent bond?

  Covalent bond is a shared pair of electrons between two non-metals
• Describe the structure and properties of simple molecular covalent substances

  - Do not conduct electricity

  - Small molecules

  - Weak intermolecular forces, therefore:

  -Low melting points and boiling points
• How do intermolecular forces change as the mass/size of the molecule increases

  They increase. That causes melting/boiling points to increase as well (more energy needed to overcome these forces (more energy needed to overcome these forces ).
• What are polymers?

  Polymers are very large molecules (>100s, 1000s of atoms) with atoms linked by covalent bonds.
• What are giant covalent structures?

  - Solids, atoms covalently bonded together in a giant lattice.

  - High melting/boiling point - strong covalent bonds.

  - Mostly don't conduct electricity (no delocalised e^-)
• Giant covalent structure examples

  Diamond, graphite, silicon dioxide
• What is metallic bonding?

  Forces of attraction between delocalised electrons and nuclei of metal ions.
• Describe the properties of metals

  - High melting/boiling points (strong forces of attraction)

  - Good conductors of heat and electricity (delocalised electrons)

  - Malleable, soft (layers of atoms can slide over each other whilst maintaining

  the attraction forces)
• What are alloys? Why are they harder than pure metals?

  Alloys:

  - Mixtures of metal which other elements, usually metals

  - different sizes of atoms distort the layers, so they can't slide over each other, therefore alloys are harder than pure metals
• What are the limitations of the simple model?


  There are no forces between spheres and atoms, molecules and ions are solid spheres - this is not true
• What are the three states of matter?

  solid, liquid, gas
• How are the particles arranged in a solid?

  Particles are very close together in a regular pattern
• What is the movement of particles in a liquid?

  Particles move around each other
• How does the energy of particles in a gas compare to that in a solid?

  Particles in a gas have the highest energy
• What are the characteristics of solids, liquids, and gases?

  • Solids:
  • Fixed shape
  • Cannot flow
  • Cannot be compressed
  • Liquids:
  • Flow and take the shape of their container
  • Cannot be compressed
  • Gases:
  • Flow and completely fill their container
  • Can be compressed
• What must happen for a substance to change state?

  Energy must be transferred by heating
• What happens to particles during melting?

  Particles gain energy to break some of the bonds between them
• How does evaporation differ from boiling?

  Evaporation occurs from the surface of a liquid, while boiling forms bubbles throughout the liquid
• What determines the amount of energy needed to change state?

  The strength of the forces between the particles of a substance
• What happens to energy during condensing or freezing?

  Energy is transferred from the substance to the surroundings
• How can the state of a substance at a given temperature be predicted?

  By knowing its melting point and boiling point
• If the temperature is -200°C, what is the predicted state of oxygen?

  Liquid
• What does the particle model assume about particles?

  The particle model assumes that particles are solid spheres with no forces between them.
• Why is the assumption that particles are solid spheres considered a limitation of the particle model?

  Because particles are not solid, as atoms are mostly empty space.
• What is a limitation of the particle model regarding the shape of particles?

  Many particles are not spherical.
• What is an ion?

  An ion is an atom or group of atoms with a positive or negative charge.
• How do ions form?

  Ions form when atoms lose or gain electrons to obtain a full outer shell.
• What happens to metal atoms when they form ions?

  Metal atoms lose electrons to form positively charged ions.
• What happens to non-metal atoms when they form ions?

  Non-metal atoms gain electrons to form negatively charged ions.
• What is the electronic structure of ions formed from metal atoms?

  The ions formed have the electronic structure of a noble gas, with a full outer shell.
• What is formed when a metal reacts with a non-metal?

  Positive and negative ions form when a metal reacts with a non-metal.
• What is an ionic bond?

  An ionic bond is formed by the strong attraction between oppositely charged ions.
• What does a dot and cross diagram represent?

  A dot and cross diagram models the transfer of electrons from metal atoms to non-metal atoms.
• What is an ionic lattice?

  An ionic lattice is a giant structure of ions with a regular, repeating arrangement.
• What holds an ionic lattice together?

  An ionic lattice is held together by strong electrostatic forces of attraction between oppositely charged ions.
• What are the properties of ionic compounds?

  Ionic compounds have regular structures called giant ionic lattices and exhibit strong electrostatic forces of attraction.
• Why do ionic compounds have high melting and boiling points?

  Ionic compounds have high melting and boiling points due to strong electrostatic forces of attraction between oppositely charged ions.