Properties and bonding structures

• Types of strong chemical bonds

  • Ionic
  • Covalent
  • Metallic
• Particles in different types of bonding

  • Ionic: Oppositely charged ions

  Covalent: Atoms which share electrons

  Metallic: Atoms which share delocalised electrons
• Ionic bonding


  Occurs when metals combine with non-metals
• Bonding in carbon dioxide

  Covalent, because it is between two non-metals
• What happens to electrons in ionic bonding

  They are transferred
• Electronic structure of ions produced by metals in Groups 1 and 2 and non-metals in Groups 6 and 7

  Electronic structure of a noble gas

  
• Link between charge number on ions in Groups 1, 2 and 3 and their group number

  Charge number is same as group number

  
• Ionic compound


  Giant structure of ions
• How ionic compounds are held together


  Strong electrostatic forces of attraction between oppositely charged ions
• Ball and stick model is not an accurate representation of the structure of an ionic compound
• How potassium and chlorine atoms join to form ions

  Potassium loses an electron to become a positive ion, chlorine gains an electron to become a negative ion
• Using a model to work out the empirical formula of sodium chloride

  • The model shows a 1:1 ratio of sodium to chlorine, so the empirical formula is NaCl

  
• Ionic

  One of the three types of strong chemical bond
• Covalent


  One of the three types of strong chemical bond
• Metallic


  One of the three types of strong chemical bond
• Ionic bonding


  Oppositely charged ions
• Covalent bonding


  Atoms which share electrons
• Metallic bonding


  Atoms which share delocalised electrons
• Ionic bonding occurs when metals combine with non-metals
• Covalent bonding occurs in carbon dioxide because it is between two non-metals
• Metallic bonding occurs in alloys
• Electronic structure of ions from Groups 1, 2, 6 and 7


  Electronic structure of a noble gas

  
• Charge number on ions in Groups 1, 2 and 3


  Same as Group number

  
• What holds ionic compounds together

  Strong electrostatic forces of attraction between oppositely charged ions
• Ball and stick model is not an accurate representation of ionic compound structure
• Ionic bonding


  • Potassium and chlorine atoms joining to form ions
• Determining empirical formula from sodium chloride model

  Count number of each type of atom and work out simplest whole number ratio

  
• Covalent bonding


  Atoms share pairs of electrons to form strong bonds
• Types of covalently bonded substances

  • Small molecules
  • Very large molecules
  • Giant covalent structures
• Limitations of dot and cross diagrams for covalent bonds
• Arrangement of atoms in metals

  Giant structures of atoms in regular pattern, with delocalised electrons
• Why metallic bonds are strong

  Sharing of delocalised electrons
• Covalent bonding


  • Water (H2O)
• Arrangement of particles in metals

  Atoms arranged in rows, with a sea of delocalised electrons
• Why metal particles are positively charged


  Metal atoms lose outer shell electrons, so there are more protons (+) than electrons (-)
• Delocalised electrons


  Free-moving electrons within the structure, not associated with a particular atom
• There are three states of matter: solid, liquid, gas
• Solid


  Particles close together in regular pattern, vibrating on the spot
• Liquid


  Particles close together in random arrangement, moving around each other
• Gas


  Particles far apart in random arrangement, moving quickly