Topic 2 - Bonding , structure and the properties of matter

• What are compounds?

  Substances with 2 or more elements combined
• How many types of strong chemical bonds are there?

  Three types
• What are the three types of strong chemical bonds?

  Ionic, covalent, and metallic
• What are the particles in ionic bonds?

  Oppositely charged ions
• In which compounds do ionic bonds occur?

  Compounds formed from metals and non-metals
• What particles are involved in covalent bonds?

  Atoms that share pairs of electrons
• Where do covalent bonds typically occur?

  In most non-metallic elements and compounds
• What particles are involved in metallic bonds?

  Atoms that share delocalised electrons
• Where do metallic bonds occur?

  In metallic elements and alloys
• What is the result of ionic bonding between metals and non-metals?

  Electrons are transferred from metal to non-metal
• 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 is an ion?

  An atom that has lost or gained electrons
• Which groups of metals and non-metals produce ions with full outer shells?

  Metals in Groups 1 and 2, non-metals in Groups 6 and 7
• What electronic structure do ions produced by metals and non-metals achieve?

  Same as a noble gas (Group 0 element)
• How can electron transfer in ionic compounds be represented?

  By a dot and cross diagram
• What are the characteristics of ionic bonding?

  • Metal + Non-metal combination
  • Electrons transferred from metal to non-metal
  • Metal becomes positively charged ion
  • Non-metal becomes negatively charged ion
• What are the characteristics of covalent bonding?

  • Atoms share pairs of electrons
  • Occurs in non-metallic elements
  • Forms molecules
• What are the characteristics of metallic bonding?

  • Atoms share delocalised electrons
  • Occurs in metallic elements
  • Forms alloys
• What is the structure of ionic compounds?

  A giant structure of ions
• How are ionic compounds held together?

  By strong electrostatic forces of attraction
• In what direction do the forces in ionic compounds act?

  In every direction
• What are the charges of sodium and chloride ions?

  Na+ and Cl-
• What is covalent bonding?

  Atoms share one or more pairs of electrons
• Name some small molecules with strong covalent bonds.

  HCl, H2, O2, Cl2, NH3, CH4
• What are polymers?

  Large covalently bonded molecules
• What do giant covalent structures consist of?

  Many atoms covalently bonded in a lattice
• What are the different ways to represent covalent substances in diagrams?

  • Dot and cross diagrams
  • Repeat units for polymers with single lines
  • Ball and stick models
  • Two and three-dimensional diagrams
• What is metallic bonding?

  Bonding of positive ions and delocalised electrons
• What are delocalised electrons?

  Electrons lost from atoms to form positive ions
• How do delocalised electrons behave in metallic structures?

  They are free to move through the structure
• Why are metallic bonds considered strong?

  Delocalised electrons are shared throughout the structure
• What are the three states of matter?

  Solid, liquid, and gas
• What occurs at the melting point?

  Melting and freezing take place
• What happens at the boiling point?

  Boiling and condensing take place
• How does particle theory explain state changes?

  • Energy needed for state change depends on particle forces
  • Nature of particles depends on bonding and structure
  • Stronger forces lead to higher melting and boiling points
• How does the strength of forces between particles affect state changes?

  Stronger forces increase melting and boiling points
• What are the limitations of the simple particle model?

  • No forces are represented
  • All particles are shown as spheres
  • Spheres are depicted as solid
• How are the states of matter represented in chemical equations?

  Solid (s), liquid (l), gas (g), aqueous (aq)
• What type of structure do ionic compounds have?

  Giant ionic lattices