3. Ionic bonding (metal + non-metal)
Ionic bonds form a giant lattice structure

4. Sodium chloride
Sodium chloride is an ionic compound formed by the reaction between the metal sodium and the non-metal chlorine.
sodium Na
chlorine Cl
sodium chloride
NaCl +
During the reaction, one electron is transferred from each sodium atom to each chlorine atom.

5. Sodium chloride - + 2.8.1 [2.8]+ 2.8.7 [2.8.8]-
Chlorine has 7 electrons in its outer shell. If it gains 1 electron, it will completely fill its outer shell.
Sodium has 1 electron in its outer shell. If it loses this electron, it will have no partially-filled shells. - Na Cl Cl Na +
2.8.1
[2.8]+
2.8.7
[2.8.8]-

6. Sodium chloride
The positive sodium ions and the negative chloride ions are strongly attracted to each other and form an ionic bond. Cl - Na +

7. Lithium Oxide Li Li + 2- O O
2.1
[2]+ Li Li +
2.6
[2.8]2-

8. Magnesium fluoride - F F Mg Mg 2+
2.7
[2.8]- - F F
2.8.2
[2.8]2+

9. Magnesium Oxide Explain how magnesium oxide is formed.
Magnesium loses 2 electrons
Oxygen gains 2 electron
Magnesium becomes 2+ ion
Oxygen becomes 2- ion
Held to together in ionic lattice

10. Calcium chloride - CaCl2
Explain how CaCl2 is formed:
Calcium loses 2 electrons
Each chlorine atom gains 1 electron
Two chlorine atoms needed
Forms ionic bond

14. Covalent bonding (non-metal + non-metal)
Giant covalent structures
Simple molecules

15. H H H H Simple molecules HYDROGEN H H WAYS TO REPRESENT THE MOLECULE
Hydrogen atom needs one electron to complete its outer shell
Another hydrogen atom also needs one electron to complete its outer shell
H H
atoms share a pair of electrons to form a single covalent bond
A hydrogen MOLECULE is formed

16. H Cl H Cl Cl Simple molecules HYDROGEN CHLORIDE H
Hydrogen atom also needs one electron to complete its outer shell
Chlorine atom needs one electron to complete its outer shell
WAYS TO REPRESENT THE MOLECULE
H Cl
H Cl
atoms share a pair of electrons to form a single covalent bond

17. AMMONIA H N H N H N H H Simple molecules H H H
WAYS TO REPRESENT
THE MOLECULE
H N H H
H N H H N
Each hydrogen atom needs one electron to complete its outer shell H
Nitrogen atom needs 3 electrons to complete its outer shell H
Nitrogen can only share 3 of its 5 electrons otherwise it will exceed the maximum of 8
A LONE PAIR REMAINS

19. Covalent bonding - molecules
Hydrogen - H2 (g)
Oxygen - O2 (g)
Chlorine - Cl2 (g)
Hydrogen chloride
HCl (g)
Methane – CH4 (g)
Water – H2O (l)
Ammonia – NH3 (g)

20. Limitations of using models – doesn’t show the shape

24. In a metal the atoms LOSE SEVERAL OF THEIR OUTER ELECTRONS which drift around between the metal ions as FREE ELECTRONS.
Atoms become POSITIVE ions because they have LOST electrons
Free (“delocalised”) electrons

25. Metallic bonding
Metals have a structure of positive metal ions held together by a “sea” of electrons – causes electrostatic attraction
We call these electrons delocalized
Ions are arranged in layers
Forms a giant lattice structure

30. Predicting states using melting and boiling points
Substance
Melting Point (˚C)
Boiling Point
(˚C)
State at room temperature
Water
99.98
Liquid
Carbon Dioxide
-78
-57
Gas
Methane
-182
-164
Hydrogen
-259.1
-252.8
Ammonia
-77.73
-33.34
Melting point
Boiling point
Solid
Liquid
Gas

32. State Symbols NaOH (aq) → Na+ (aq) + OH– (aq) (s) – solid (l) – liquid
(g) – gas
(aq) – dissolved in water
NaOH (aq) → Na+ (aq) + OH– (aq)

34. Properties of ionic compounds – giant lattices
High Melting point – lots of ENERGY needed to break the strong bonds (strong electrostatic attraction) Solubility - Can dissolve in water which enables the ions to move Conduction - When MOLTEN or DISSOLVED IN WATER, ionic compounds can conduct electricity because the ions can carry current/charge (not electricity)

41. Covalent bonding – simple molecules
Properties of covalent compounds
A covalent bond is a shared pair of electrons
Substances that consist of simple molecules are gases, liquids or solids that have relatively low melting points and boiling points due to weak intermolecular bonds
They do not conduct electricity because the molecules do not have an overall electric charge. No free electrons or ions.
Hydrogen - H2 (g)
Oxygen - O2 (g)
Chlorine - Cl2 (g)
Methane – CH4 (g)
Hydrogen chloride
HCl (g)
Ammonia – NH3 (g)
Water – H2O (l)

47. Polymers Molecules are linked with strong covalent bonds
Intermolecular forces between polymers are relatively strong
Polymers are usually solid at room temperature

50. Carbon structures - diamond
Giant covalent structure of diamond
Diamond
Diamond is made only from carbon atoms.
Every carbon makes four covalent bonds to achieve a full outer shell.
Every carbon atom is bonded to four other carbon atoms.
This means the structure keeps on growing!
We make a Giant Covalent Structure.
Key properties –
Diamond is very hard.
High melting points – because it has strong covalent bonds (which take a lot of energy to break)

52. Carbon structures - graphite
Giant covalent structure of graphite
Graphite
Graphite is made only from carbon atoms.
Every carbon makes 3 covalent bonds to achieve a full outer shell.
Forms hexagonal rings, arranged in layers
Weak intermolecular forces between the layers
Every carbon atom is bonded to three other carbon atoms
Key properties –
High melting point
Graphite is very soft.
Conducts electricity – free electrons
Slippery – arranged in layers

61. Metallic bonding – giant structures
Conducts electricity and heat
Delocalised electrons can move through the structure
Malleable
Ions arranged in layers so ions are able to slide over each other
High melting and boiling points
Ions held together by strong electrostatic attraction so needs a lot of energy to break the bonds

62. Metallic bonding - alloys
Mixture of metals of different sizes.
Distorts the layers
Layers can’t slide

70. Covalent bonding - Giant
Besides graphite and diamond, carbon can also form another type of giant covalent structure.
Fullerenes (named after the scientists that discovered them) are made by conjoined hexagonal carbon rings
Possible uses of Fullerenes in the future could be:
Drug delivery
In lubricants
As catalysts in reactions
To make carbon nanotubes to reinforce structures

72. Nano particles
Structures that are 1-100nm in size, or of the order of a few hundred atoms
Particle name
Symbol
Diameter (nm)
Diameter (m)
Nano particle
Smaller than PM2.5
100 – 2500 nm
1 x 10-7m – 2.5 x 10-6 m
Coarse particle
PM10
2500nm – nm
2.5 x 10-6 m – 1 x 10-5 m

73. Nano particles

75. Nanoparticles Large surface area makes them effective catalysts.
Advantages
Disadvantages
Large surface area makes them effective catalysts.
Nanotubes can be used in small scale circuits as nanowires.
So small they can enter the skin and therefore the bloodstream.
Easily become airborne, breathing in can potentially damage the lungs.
Nanoparticles are present in sun screens
May be used to develop faster computers, lighter construction materials and new coatings