ionic bond

We know simple and complex ions. Both can participate in an ionic bond.
As soon as ions attract each other - because they have opposit charges - you can get an ionic bond.

The bigger purple spheres represent, for example, the negative ions, anbd the grey smaller spheres are the positive metal ions.

You know: there are two kinds of ions: negative and positive ones.
They always are charged, otherwise they wouldn't be ions.

In general, the metal ions will make positive ions (metal atoms like to donate electrons), and the non metal atoms form negative ions (because non metal ions prefer to gain electrons).
In other words: if a metal and a non metal react, electrons are transferred from the metal to the non metal.
That's how positive and negative ions are made; they will immediately attract each other.
Don't forget: the properties of a neutral atom are completely different from the properties of the according ion.
For example: Na, Cl and F in neutral situation are poisonous, but as ions they are found in kitchen salt and in fluorine tablets.

The IONIC bond


attraction between positive and negative particles.

Opposite charges attract each other; equal charges to repell

The force of repulsion or attraction depends on:
  1. how big the charges are
  2. how close the charges are
For this we apply the formula of Physics (there is the Law of Coulomb again):

k = a constant
Q1 and Q2 are the charges of the ions
n = the distance (measured from center point to center point; look in a table with ionic rays.

You must always mind: if a neutral substance contains positive ions, there must be negative ions (same total charge) in that substance.
A metal in a compound has before reacted and donated its valency electrons.
That's how you got a positieve charged metal particle.
The valency electrons were transferred to the non metal part, that, of course, became negative.

Another way to say the same:
If you have a connection, a bonding, wherein metals and non metals are present, the metal part has always donated electrons, and is thus positive; The rest of that compound must be negative.
If you see that a chemical compound, a substance, contains a metal, than there is an ionic bond. [an exception may be a compound with an ammonia ion]

If we write ions separately, the charge always must be indicated right above, also if complex ions are involved.
If a substance has a charge of 0, so if there is equal amount of + and -, than don't write any charge in the total formula.

Na+ + Cl- NaCl
I2 + I- I3-

The name 'fluorine tablet' in fact, a better name should be: fluoride tablets!

If non metals have made negative ions, their name will change with a suffix: you add: -ide.

Cl- = chloride; O2- = oxyde S2- = sulfide N3- = nitride

Positive ions do not get such a name change.
In the case of a metal with various valencies (ex: Iron ions can be 2+ or 3+) than you must indicate with a Roman number the right valency in the name of the ion:
iron(II)chloride = FeCl2 (ions Fe2+ and Cl-) The Iron has here a valency of 2
lead(IV)oxyde = PbO2 (ions: Pb4+ and O2-) The Lead has here a valency of 4

A metal is a free element, red Copper for example, or Tin, did not react yet; the atoms still have their valency electrons and still are neutral.