1.1 Formulae of Ionic Compounds 1.1.1 Ratio of Ions in Ionic Compounds 1.1.1.1 Example(1) Cross Method(A) Calcium Chloride 1.1.1.1 Example(1) Cross Method(B) Aluminium Sulphate 1.1.1.2 Example(2) Jig-saw Method(A) Calcium Chloride 1.1.1.2 Example(2) Jig-saw Method(B) Aluminium Sulphate 1.1.1.3 Questions on Cross Method Level 1 Questions 1.1.1.3 Questions on Cross Method Level 2 Questions 1.1.1.4 Questions on Jig-saw Method Level 1 Questions 1.1.1.4 Questions on Jig-saw Method Level 2 Questions 1.1.2 Number of Ions from an Ionic Compounds 1.1.2.1 Questions on Total Number of Ions from an Ionic Compounds
1.1 Formulae of Ionic Compounds When metals react with non-metals, ionic compounds are formed. Common practice: write positive ions before negative ions. e.g. sodium chloride, (NaCl), NOT chloride sodium (ClNa). The rules for writing the formulae of ionic compounds are discussed below.