1. Try this in the back of your book.
What is an atom? Can you think of any examples of atoms?

2. Elements
An element is the simplest substance. All the particles are the same and they are found on the Periodic Table.
All of these diagrams are of elements. The first box shows an element in the solid state e.g. Fe, the second a diatomic gas e.g O2 and the last a monatomic gas e.g. he.

3. The Periodic Table
Explain that all the elements known are listed on the Periodic Table.
Note that columns are call groups and rows are called periods.
Shade in the metals and non-metals different colours.
Label group 1 – Alkali metals
Group 2 – Alkaline Earth metals
Group 7 – Halogen
Group 0 – Noble/Inert gases
Highlight the gases at room temperature: H, He, O, N, F, Cl and all of group 0.
Highlight that Br and Hg are the only liquids at room temperature.

4. Atom anatomy - He
Label electrons, protons, neutrons, nucleus and shell. Add the particle masses and charges.
Explain that the maximum occupancy of the electron shells is

5. Atom anatomy Nucleus contains protons and neutrons electrons
orbit around the
nucleus
Point out:
That the vast majority of the mass of an atom is in the nucleus.
That most of an atom is space.
That electrons are attracted to the nucleus as they are oppositely charged.
That electrons are responsible for the chemistry of an atom.
Charge
Mass
proton +1 1
neutron 1
electron
- 1
Very small

6. Symbols Find oxygen on the Periodic table – Group 6 Mass number O 16
(number of protons and neutrons) O 16
Proton number
(number of protons = no. of electrons in an atom) 8
How many protons neutrons and electrons will one atom of oxygen contain?
Number of protons = 8
Number of neutrons = 8
Number of electrons = 8

7. Lithium Li 7 3
Write P = 3 and N=4 in the centre. Then add 2 crosses to the inner shell and one cross to the outer shell – to show the electron arrangement. Then write Note that the number of outer shell electrons is equal to the group number.
Students need to be able to draw the electronic structure in this manner for the first 20 elements.

8. Match the definition with the key word.
More than one atom chemically joined.
More than one type of atom chemically joined.
All the atoms are the same.
More than one substance not chemically joined.
Elements
Compounds
Mixtures
Molecules
1 – c
2 – b
3 – d
4 - a

9. Why do atoms Bond? Atoms want a complete outer shell of e-.
Only the noble gases (group 0) have already got this.
Atoms bond, in chemical reactions, so that they increase or decrease their outer shell. They are then more stable, with a full outer shell of e-.
There are thee types of bonding:
Covalent
Ionic
Metallic

10. Covalent bonding Draw a diagram of the electronic arrangement of Cl:
There are only 7 e- in the outer shell, Cl forms diatomic molecules (Cl2): Cl
Add electrons as dot and cross where necessary. Highlight the covalent bond by circling and state that it is a shared pair of electrons.
Cl Cl

11. Covalent bonding H H A shared pair of electrons.
Happens between non-metals.
The simplest molecule is H2.
It can also be shown as:
H H
H H

12. Dot and cross diagrams
Bonding in compounds are often shown in special diagrams. One element’s e- are dots and the other elements e- are crosses:
Sometimes the circles are missed out:
H Cl
Add dots and crosses to the diagram.

13. More than one covalent bond
Covalent bond could be double bonds:
O=O
They can even be triple bonds:
O O
Add dots and crosses to the diagram.
H C C H

14. Covalent Bonding and structure
Simple molecular
Giant molecular
Allotropes are the same element but a different structure – think about carbon.
How many different forms of C do you know? Are their properties the same? How do their structures affect the properties? Draw a diagram of each allotrope of carbon and explain their properties in terms of their structure.
Examples of simple molecular include: water, carbon dioxide, oxygen. They have low melting and boiling points, because only weak forces of attraction between the molecules need to be overcome, the covalent bonds remain.
Giant molecular include allotropes of carbon.
Diamond is crystalline, hard and with a high melting point. It is crystalline and hard because of the regular arrangement of bonds. It has a high melting point as all the covalent bonds need to be broken to melt it.
Graphite is soft, a conductor and has a high melting point. It is soft as the layers can slide over each other. It is the only non-metal conduct as there are electrons free to move between the layers. It has a high melting point as all the covalent bonds need to be broken to melt it.

15. Ionic bonding Na Cl Na Cl Draw the electronic structure of Na and Cl:
Remember bonding is about energy, these elements need to donate e-.
Na Cl
Add electrons and charges.
Na Cl

16. Simplified format + Ions can be shown as the diagrams or simplified:
becomes Na+.
Chloride ions become Cl-.
The compound is called Sodium Chloride (salt) and its overall formula is NaCl. + Na

17. Ionic Bonding Normally happens between non-metals and metals.
Ionic bonding is a transfer of e-. The ions are held by electrostatic forces.
Cations are positive, metals always produce cations.
Anions are negative, non-metals always produce anions.
The final compound must be neutral i.e. as many cations as anions.

18. A simpler way to determine ionic formula
Write the symbols of the elements side by side with the metal first and then the non-metal.
Determine the ion which each element forms to become stable, and write the charge to the top right hand of the symbol.
Cross the values of the charges down ignoring the positive or negative sign. This tells you the proportion of each element.
Ignore any ‘1’ and cancel down, and write the formula as:
Complete some examples using this step-by-step approach.
E.g.
Calcium chloride
Ca 2+ Cl 1-
Ca1Cl2
CaCl2

19. Other ions – Molecular ions
Some anions are made up of more than one element. They act as one particle. You need to know some common ones:
Nitrate = NO3-
Hydroxide = OH-
Sulphate = SO42-
Carbonate = CO32-
Phosphate = PO43-

20. Ionic structure
Millions of ions are uniformly arranged in a fixed lattice, this is called a giant structure.
There are strong electrostatic forces between ions of opposite charges.
These electrostatic forces are known as ionic bonds.

21. Metallic Bonding Must only be metal atoms.
Happens in elements or alloys.
Known as positive metal ions in a sea of electrons.

22. Metals structure and bonding

23. Metallic bonding Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+
Explain that the free roaming electrons act like glue to hold the now metal ions in position. It is the free flowing electrons that allow metals to conduct. The layers of metals can easily slide over each other and this is why a metal is malleable and ductile.
Na+
Na+
Na+
Na+

24. Metal properties
Use the metallic bonding model to explain these metal properties:
Ductile
Malleable
Conductors of heat and electricity
It is the free flowing electrons that allow metals to conduct. The layers of metals can easily slide over each other and this is why a metal is malleable and ductile.

25. These are the definitions, what are the key words?
Charged atoms.
Bonding that involves a shared pair of electrons.
Bonding that involves the transfer of electrons, with oppositely charged species being attracted.
All the particles are the same.
More than one type of atom chemically joined.
Ions
Covalent
Ionic
Element
Compound

26. Comparing Ionic and covalent chemicals - Results
Type of bonding
Appearance
Melting Point
Solubility in water
Conduction of electricity
NaCl I2
Wax
CuSO4
Complete the practical (see sheets)
NaCl: Ionic; white crystals; high; soluble; conducts in solution.
I2: Covalent; grey shiny solid; low; non-soluble; insulator.
Wax: Covalent; white solid; low; non-soluble; insulator.
CuSO4: Ionic; blue crystals; high; soluble; solution conducts.

27. Conduction Covalent compounds do not conduct.
Ionic compounds conduct when the ions are free to move (either molten or in aqueous solution).