1. IONIC BONDING

2. HOW DOES IT WORK?
Ionic bonding takes place between metals and non-metals
Metal atoms try to attain noble gas strucure (full outer shells) by losing electrons to form positive ions
Non-metal atoms try to attain noble gas strucure (full outer shells) by gaining electrons to form negative ions
The positive and negative ions formed attract each other to give an ionic bond.

3. Sodium Chloride

4. Sodium has atomic number 11
It therefore has 11 protons in its nucleus + + + + + + + + + + +
It also has 11 electrons
2 in the inner shell
8 in the next shell
1 in the outer shell
Sodium has 11 protons = 11 + charges
Sodium has 11 electrons = 11 - charges
Total = 0. It is a neutral atom

5. CHLORINE Chlorine has atomic number 17
The number of protons in its nucleus is 17 + + + + + + + + + + + + + + + + +
The number of electrons is 17
In the inner shell 2
In the next shell 8
In the outer shell 7
Chlorine has 17 protons = 17 + charges
It also has 17 electrons = 17 - charges
TOTAL = 0. It is a neutral atom

6. - + Both Atoms want complete outer shells of electrons Sodium Atom
Sodium Ion
Chloride Ion
Chorine Atom - +
Sodium loses one electron to gain noble gas structure (complete outer shell)
Chlorine gains the electron and also gets a complete outer shell of 8 electrons
Now the sodium has
11protons (still) = 11+ charges
The chlorine has
17protons (still) = 17+ charges
But only 10 electrons = 10- charges
But only 18 electrons = 18- charges
Total = +1 which is the charge on the SODIUM ION
Total = -1 which is the charge on the CHLORIDE ION

7. Magnesium Oxide

8. Magnesium has atomic Number 12 Oxygen has atomic Number 8
It therefore has 12 protons in the nucleus
It therefore has 8 protons in the nucleus
And 12 electrons arranged 2.8.2
And 8 electrons arranged 2.6 2+ 2- 8p
12p
Magnesium needs to lose 2 electrons to get a complete outer shell
Oxygen needs to gain 2 electrons to get a complete outer shell
Magnesium still has 12 protons = 12+
But only 10 electrons = 10 –
So overall charge = 2+
The ion is written Mg2+
Oxygen still has 8 protons = 8+
But now 10 electrons = 10 –
So overall charge = 2-
The ion is written O2-

9. Magnesium Fluoride

10. This gives us the Mg2+ ion And two F- ions
MAGNESIUM
FLUORINE
Magnesium has atomic Number 12
Fluorine has atomic Number 9
It therefore has 12 protons in the nucleus
It therefore has 9 protons in the nucleus
And 12 electrons arranged 2.8.2
And 8 electrons arranged 2.7 8p 8p
12p
Magnesium needs to lose 2 electrons to get a complete outer shell
But Fluorine needs to gain only 1 electrons to get a complete outer shell
Therefore another fluorine is needed
This gives us the Mg2+ ion
And two F- ions
The formula is MgF2

11. IONIC STRUCTURES

12. Now opposite charges attract!
POSITIVE ION
NEGATIVE ION
Now opposite charges attract!
Positive ions and negative ions form a lattice .
Every positive ion is surrounded by negative ions and every negative ion is surrounded by positive ions.

13. PROPERTIES OF IONIC COMPOUNDS
They are crystalline solids
They have high melting points
Many dissolve in water
If melted or dissolved in water, they conduct electricity.
Salt Crystals (sodium chloride)
Copper Sulphate crystals