1.37   draw a simple diagram to represent the positions of the ions in a crystal of sodium chloride.

You can draw a simple cube (left) and then extend it by a few ions around either an Na+ or a Cl- ion to show that each ion is surrounded by six others. You don’t need to draw the whole thing on the right.

Be sure to label the ions.

(note how the shape of sodium chloride crystals reflects the shape of the lattice)