Ionic compounds have a structure called a giant ionic lattice
The ions form a closely packed regular lattice arrangement and there are very strong electrostatic forces of attraction between oppositely charged ions
In all directions in the lattice
A single crystal of sodium chloride(table salt) is one giant ionic lattice
The Na+ and Cl- ions are held together in a regular lattice
The lattice can be represented in different ways:
A model could show the relative sizes of the ions as well as the regular pattern of an ionic crystal, but it only lets you see the outer layer of the compound
A model could show a ball and stick model
It would show the regular pattern of an ionic crystal and show how all the ions are arranged
It also suggest that the crystal extend beyond what’s shown in the diagram
The model isn’t to scale so the relative sizes of the ions may not be shown
Also in reality there aren’t gaps between the ions
Ionic compounds all have similar properties
They all have high melting and boiling points due to the many strong bonds between the ions
It tales lots of energy to overcome this attraction
When they’re solid, the ions are held in place, so the compounds can’t conduct electricity
When ionic compounds melt, the ions are free to move and they’ll carry electric current
Some ionic compounds also dissolve in water
The ions separate and are all free to move in the solution, so they’ll carry electric current
Look at charges to find the formula of an ionic compound
You might have to work out the empirical formula of an ionic compound from a diagram of the compound
If it’s a dot and cross diagram, count up how many atoms there are of each elements
Write this down to give you the empirical formula
If you’re given a 3D diagram of the ionic lattice, use it to work out what ions are in the ionic compound
You’ll then have to balance the charges of the ions so that the overall charge on the compound in zero