4.1.1 Describe the ionic bond as the electrostatic attraction between oppositely charged ions.
4.1.2 Describe how ions can be formed as a result of electron transfer.
4.1.3 Deduce which ions will be formed when elements in Groups 1, 2 and 3 lose electrons.
Cations: Positive
4.1.4 Deduce which ions will be formed when elements in Groups 5, 6 and 7 gain electrons.
Anions: Negative
4.1.5 State that transition elements can form more than one ion.
4.1.6 Predict whether a compound of two elements would be ionic from the position of the elements in the Periodic Table or from their electronegativity values.
4.1.7 State the formula of common polyatomic ions formed by non-metals in Periods 2 and 3.
4.1.8 Describe the lattice structure of ionic compounds.
- Ionic bond: the electrostatic attraction between oppositely charged ions that build up to form a strong lattice
4.1.2 Describe how ions can be formed as a result of electron transfer.
- Ion: charged particle that form from atoms or groups of atoms by loss or gain of one or more electrons. Electrons are transferred from one atom to another to form ions with complete outer shells of electrons
4.1.3 Deduce which ions will be formed when elements in Groups 1, 2 and 3 lose electrons.
Cations: Positive
4.1.4 Deduce which ions will be formed when elements in Groups 5, 6 and 7 gain electrons.
Anions: Negative
4.1.5 State that transition elements can form more than one ion.
- Transition elements have an electron configuration that enables them to lose different numbers of electrons from their d sub-shell and so form different ions with different charges.
4.1.6 Predict whether a compound of two elements would be ionic from the position of the elements in the Periodic Table or from their electronegativity values.
- Position: metal on left, non-metal on right. Highest tendency to form from bottom left and top right
- Electronegativity: if the difference is greater than 1.8 the compound is predominantly ionic
4.1.7 State the formula of common polyatomic ions formed by non-metals in Periods 2 and 3.
- Nitrate NO3–
- Carbonate CO32–
- Chlorate ClO3–
- Sulfate SO42–
- Chromate CrO42–
- Phosphate PO43–
- Hydroxide OH–
- Hydrogensulfate HSO4–
- Hydrogencarbonate HCO3–
- Ethanoate CH3COO–
4.1.8 Describe the lattice structure of ionic compounds.
- Ions surround themselves with the opposite charge forming a crystalline structure
- Cations smaller than anions
- Grow indefinitely based on coordination number and ratio
- The higher the charges on the ions and the smaller their size, the larger the lattice enthalpy and the more energetically stable the ionic compound