Structure 2.1 The ionic model    
Structure 2.1.1
Understandings:
  • When metal atoms lose electrons, they form positive ions called cations. When non-metal atoms gain electrons, they form negative ions called anions.
Learning outcomes:
  • Predict the charge of an ion from the electron configuration of the atom.
Additional notes:
  • The formation of ions with different charges from a transition element should be included.
Linking questions:
  • Structure 3.1 How does the position of an element in the periodic table relate to the charge of its ion(s)
  • Structure 1.3 (HL) How does the trend in successive ionisation energies of transition elements explain their variable oxidation states?
This video covers the formation of positive ions (cations) and negative ions (anions). 
Structure 2.1.2
Understandings:
  • The ionic bond is formed by electrostatic attractions between oppositely charged ions.
  • Binary ionic compounds are named with the cation first, followed by the anion. The anion adopts the suffix “ide”.
Learning outcomes:
  • Deduce the formula and name of an ionic compound from its component ions, including polyatomic ions.
  • Interconvert names and formulas of binary ionic compounds.
Additional notes:
  • The following polyatomic ions should be known by name and formula: ammonium, hydroxide, nitrate,  hydrogencarbonate, carbonate, sulfate and phosphate.
Linking questions:
  • Reactivity 3.2 Why is the formation of an ionic compound from its elements a redox reaction?
  • HL Structure 2.2 How is formal charge used to predict the preferred structure of sulfate?
  • HL Reactivity 3.1 Polyatomic anions are conjugate bases of common acids. What is the relationship between their stability and the conjugate acid’s dissociation constant, Ka?
This video covers ionic bonding and the structure of ionic compounds. 
This video covers the naming and formulas of ionic compounds. 
This video covers polyatomic ions. 
Structure 2.1.3
Understandings:
  • Ionic compounds exist as three-dimensional lattice structures, represented by empirical formulas.
Learning outcomes:
  • Explain the physical properties of ionic compounds to include volatility, electrical conductivity and solubility.
Additional notes:
  • Include lattice enthalpy as a measure of the strength of the ionic bond in different compounds, influenced by ion radius and charge.
Linking questions:
  • Structure 3.1 How can lattice enthalpies and the bonding continuum explain the trend in melting points of metal chlorides across period 3?
This video covers the properties of ionic compounds (solubility, melting point and electrical conductivity). 
Factors that affect lattice enthalpy
This video covers the factors that affect lattice enthalpy. 
Factors that affect lattice enthalpy
  • There are two factors that affect the value of the lattice enthalpy, the charge on the ions and the ionic radius of the ions.
  • Ions with a higher charge have a stronger force of attraction, therefore a higher lattice enthalpy.
  • Smaller ions have a stronger force of attraction, therefore a higher lattice enthalpy.