Bonding-NOTES

• What type of elements does ionic bonding occur between?

  A metal and a non-metal
• What happens to electrons during ionic bonding?

  Electrons are transferred from the metal to the non-metal
• What are the charged particles created during ionic bonding called?

  ions
• What type of forces attract oppositely charged ions in ionic bonding?

  Electrostatic forces
• What is a giant ionic lattice?

  A structure formed by the attraction of oppositely charged ions
• What ions are formed in sodium chloride?

  Na⁺ and Cl^-
• How does sodium chloride achieve a full outer electron shell?

  Sodium loses an electron and chlorine gains an electron
• What are some common compound ions?

  • Sulfate: SO₄^2-
  • Hydroxide: OH^-
  • Nitrate: NO₃^-
  • Carbonate: CO₃^2-
  • Ammonium: NH₄⁺
• What type of elements do covalent bonds form between?

  Two non-metals
• How are electrons involved in covalent bonding?

  Electrons are shared between the two outer shells
• What can multiple electron pairs produce in covalent bonding?

  Multiple covalent bonds
• How can shared electron pairs be represented?

  Using dot and cross diagrams
• What is a dative bond?

  A bond where both electrons in the shared pair are supplied from a single atom
• How is a dative bond indicated in diagrams?

  With an arrow from the lone electron pair

  
• What happens to a dative bond once it has formed?

  It is treated as a standard covalent bond
• What is metallic bonding characterized by?

  A lattice of positively charged ions surrounded by delocalised electrons

  
• What does the 'sea' of delocalised electrons in metallic bonding produce?

  A strong electrostatic force of attraction

  
• How does the charge on the positive ion affect the attractive force in metallic bonding?

  The greater the charge, the stronger the attractive force
• How does the size of an ion affect the attraction in metallic bonding?

  Larger ions produce a weaker attraction
• What are physical properties of a substance?

  Boiling point, melting point, solubility, and conductivity
• How do physical properties differ among substances?

  They differ depending on the type of bonding and crystal structure
• What are the four main types of crystal structure?

  • Ionic
  • Metallic
  • Simple molecular
  • Macromolecular
• What is a characteristic of substances with an ionic crystal structure?

  They have a high melting and boiling point
• Why do ionic substances conduct electricity when molten or in solution?

  Because the ions separate and are free to move
• What happens to ionic substances when layers of charges are distorted?

  They become brittle and break apart
• What is a characteristic of substances with a metallic structure?

  They are good conductors of electricity
• Why are metals malleable?

  Because layers of positive ions can slide over one another
• What is the melting point characteristic of metallic substances?

  They have high melting points
• What is a characteristic of substances with a simple molecular structure?

  They consist of covalently bonded molecules held together by weak van der Waals forces
• Why do simple molecular substances have low melting and boiling points?

  Because weak van der Waals forces require little energy to overcome
• What is unique about water's boiling point despite its simple molecular structure?

  It has an unusually high boiling point due to hydrogen bonding
• Why are simple molecular substances poor conductors of electricity?

  Because they contain no charged particles
• What is a characteristic of macromolecular structures?

  They are covalently bonded into a giant lattice structure
• What gives macromolecular substances a very high melting point?

  The strength of the covalent lattice
• What makes diamond one of the hardest materials known?

  Each carbon atom is bonded to four other carbon atoms

  
• How does graphite differ from diamond in its structure?

  Graphite has carbon atoms bonded in flat sheets

  
• Why can graphite conduct electricity?

  Because it has free electrons that move between layers
• What determines the shape of a molecule?

  The number of electron pairs around the central atom
• How do electron pairs affect bond angles in a molecule?

  They repel each other to create the largest bond angle possible
• What effect do lone pairs have on bond angles?

  They provide additional repulsive forces, reducing the bond angle