Bonding, Structure and the Properties of Matter

• What are compounds?

  Substances in which 2 or more elements are chemically combined
• What are the three types of strong chemical bonds?

  Ionic, covalent, and metallic

  
• What characterizes ionic bonds?

  Particles are oppositely charged ions

  
• In which types of compounds do ionic bonds occur?

  In compounds formed from metals combined with non-metals

  
• What defines covalent bonds?

  Particles are atoms which share pairs of electrons

  
• Where do covalent bonds typically occur?

  In most non-metallic elements and in compounds of non-metals

  
• What is the nature of metallic bonds?

  Particles are atoms which share delocalised electrons

  
• In which materials do metallic bonds occur?

  In metallic elements and alloys

  
• What happens to electrons in ionic bonding between a metal and a non-metal?

  Electrons in the outer shell of the metal atom are transferred

  
• What occurs to metal atoms during ionic bonding?

  Metal atoms lose electrons to become positively charged ions

  
• What happens to non-metal atoms during ionic bonding?


  Non-metal atoms gain electrons to become negatively charged ions

  
• What is an ion?

  An atom that has lost or gained electron(s)
• Which groups of elements produce ions that achieve a full outer shell of electrons?

  Metals in Groups 1 and 2 and non-metals in Groups 6 and 7

  
• What electronic structure do ions produced by metals and non-metals achieve?

  The same electronic structure as a noble gas (Group 0 element)

  
• How can electron transfer during the formation of an ionic compound be represented?


  By a dot and cross diagram

  
• What is the structure of ionic compounds?

  A giant structure of ions

  
• How are ionic compounds held together?

  By strong electrostatic forces of attraction between oppositely charged ions

  
• Why do the forces in ionic compounds act in every direction?

  Because the structure is in 3D
• Give an example of an ionic compound.

  Sodium chloride (salt)
• What is covalent bonding?

  When atoms share one or more pairs of electrons

  
• Name some small molecules that have strong covalent bonds.

  HCl, H2, O2, Cl2, NH3, CH4

  
• What are polymers?

  Large covalently bonded molecules
• What are giant covalent structures (macromolecules)?

  Structures that consist of many atoms covalently bonded in a lattice structure
• Give examples of giant covalent structures.

  Diamond, silicon dioxide
• How can covalent substances be represented in diagrams?

  Using dot and cross, repeat units for polymers, ball and stick, and two- and three-dimensional diagrams

  
• What characterizes metallic bonding?

  The bonding consists of positive ions and delocalised electrons arranged in a regular pattern

  
• What is the delocalised electron system in metallic bonding?

  The electrons ‘lost’ from the atoms to form positive ions

  
• What is the movement of delocalised electrons in metallic bonding?

  They are free to move through the structure

  
• Why are metallic bonds considered strong?

  Because delocalised electrons are shared through the structure

  
• What are the three states of matter?

  Solid, liquid, and gas
• At what point do melting and freezing occur?

  At the melting point
• At what point do boiling and condensing occur?

  At the boiling point
• How does particle theory explain changes of state?

  It explains melting, boiling, freezing, and condensing based on particle behavior
• What does the amount of energy needed to change state depend on?

  It depends on the strength of the forces between the particles of the substance
• What factors influence the nature of the particles involved in a substance?

  The type of bonding and the structure of the substance
• How do the strength of forces between particles affect melting and boiling points?

  The stronger the forces, the higher the melting and boiling points
• What are the limitations of the simple particle model?

  It assumes no forces, represents particles as spheres, and depicts them as solid
• What are the state symbols used in chemical equations?

  • Solid: (s)
  • Liquid: (l)
  • Gas: (g)
  • Aqueous solution: (aq)
• What type of structures do ionic compounds have?

  Regular structures known as giant ionic lattices
• What type of forces exist in ionic compounds?

  Strong electrostatic forces of attraction between oppositely charged ions