A teacher uses coloured balls to build a model of part of a crystal of potassium iodide for a lesson. Potassium is in group 1 of the periodic table and iodine is in group 7.
State whether a potassium atom loses or gains electrons when it forms an ion.
State how many electrons an iodine atom gains when it forms an iodide ion.
State what holds the potassium ions and the iodide ions together in potassium iodide.
Give the smallest whole-number ratio of potassium ions to iodide ions in potassium iodide.
119 exam-style questions on Edexcel GCSE Chemistry 2.3 Ionic bonding, covering 2.3.1 Ions and the formation of ionic bonds, 2.3.2 Naming and deducing formulae of ionic compounds, and 2.3.3 Giant ionic lattices. Each one has a worked solution and a mark scheme showing where the marks go.