Caesium, Cs, is in group 1 of the periodic table and iodine, I, is in group 7. A student draws the outer shell of each atom for a dot-and-cross diagram of caesium iodide, using dots for electrons from caesium and crosses for electrons from iodine.
Which instructions complete a correct dot-and-cross diagram of the ions in caesium iodide?
Move the caesium dot into iodine's outer shell, draw square brackets around each particle, and label both with a 1+1+1+ charge.
Copy the caesium dot into iodine's outer shell while leaving the original dot around caesium, and show both particles without charges.
Remove the caesium dot without placing it around iodine, then label caesium Cs+\mathrm{Cs^{+}}Cs+ and leave iodine neutral.
Move the caesium dot into iodine's outer shell, draw square brackets around each particle, and label them Cs+\mathrm{Cs^{+}}Cs+ and I−\mathrm{I^{-}}I−.
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.