In Ionic Bonding, atoms lose or gain electrons to become charged particles (called Ions)
If they gain electrons, they become Negatively Charged (Because they are gaining -1 charge per electron)
If they lose electons, they become Positively Charged (Because they are losing - charge per electron, which is equal to gaining +1 charge per electron)
Ionic Bonding 2
All the atoms in the left hand side of the periodic table have just one or two electrons in their outer shell (or Highest Energy Level). And they want to get rid of them so they have a Full Outer Shell
On the other side of the table, the elements in Group 6 and 7 have almost full outer shells. So they're also keen to Gain a couple of electrons to complete their outer shell.
Ionic Bonding 3
Ionic Compounds always have Giant Ionic Lattices. The ions form a closely packed regular lattice arrangement. There are very strong electrostatic forces of attraction between oppositely charged ions, in all directions. A single crystal of Sodium Chloride is one Giant Ionic Lattice, which is why salt crystals tend to be cuboid in shape.
All ionic compounds have similar properties:
- They all have high melting points
- They all have high boiling points
- When they melt, the ions are free to move around and carry and electric current
- They are easily dissolved in water. When this happens the ions seperate and are again free to move and carry an electric current