A sodium atom has electronic configuration 2,8,12,8,12,8,1. A chlorine atom has electronic configuration 2,8,72,8,72,8,7.
Draw a diagram showing the transfer of an electron when these atoms form ions. Show only the outer-shell electrons of the starting atoms. Use a cross for the sodium electron and dots for the chlorine electrons, and an arrow to show the transfer.
Draw a dot-and-cross diagram for the ions formed. Show the chloride ion's outer-shell electrons, brackets and charges on both ions. You may represent the sodium ion by its symbol inside brackets without drawing its electron shells.
Explain what holds these ions together in sodium chloride.
56 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.