1. WJEC Additional Science
The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club The PiXL Club
DTT Booster
WJEC Additional Science 
THERAPY – Chemical bonding, structure and properties   
Commissioned by The PiXL Club Ltd. February 2016
© Copyright The PiXL Club Ltd, 2016
This resource is strictly for the use of member schools for as long as they remain members of The PiXL Club. It may not be copied, sold nor transferred to a third party or used by the school after membership ceases. Until such time it may be freely used within the member school.
All opinions and contributions are those of the authors. The contents of this resource are not connected with nor endorsed by any other company, organisation or institution.
The PiXL Club Ltd, Company number

2. How to deliver the DTT Booster
Administer the short on-line diagnosis test.
Get the responses from your Google drive.
Work through the appropriate therapy slides completing the model questions and answers.
Complete the question slides for students to self assess.
Administer the final test (peer assess)

3. Conduction and convection
WJEC Chemical bonding, structure and properties
Ionic
Covalent
Metallic
Formed between metals and non metals
Gain or lose electrons
Strong forces of attraction between molecules
High melting point and boiling point
Formed between non metals
Share a pair of electrons
Weak forces of attraction between molecules
Low melting and boiling point
Formed between metals
Force of attraction between these free electrons and metal ions.
Strong force of attraction between free electron and metal ions
High melting and boiling point
Model question
Why do ionic compounds have high melting and boiling points?
Model answer
Ionic bonds have strong forces of attraction between the molecules so have high melting and boiling points
CLICK to reveal MODEL ANSWER
P1.1.3a/P1.1.1

4. CLICK to reveal MODEL ANSWER
WJEC Chemical bonding, structure and properties
Transfer of electrons from metal to a non metal forming ions.
Held together by strong forces of attraction between oppositely charged ions.
Ionic
bonding
Metals lose electrons.
Non-metals gain electrons.
High melting and boiling points because of the strong forces of attraction.
When dissolved in water, ionic compounds form solutions in which the ions can move. This means the solution can conduct electricity.
CLICK to reveal MODEL ANSWER
Model answer
When molten or dissolved the ions are able to move and so they can conduct electricity. When solid the ions are not able to move and so cannot conduct electricity.
Model question
Why can ionic compounds only conduct electricity when molten or dissolved?

5. CLICK to reveal MODEL ANSWER
WJEC Chemical bonding, structure and properties
When you draw ionic bonds it is important that you Clearly show the movement of the electron/s  Show the electrons in their new location Show the overall charges on the ions formed.
Model Question
Draw the ionic bonding for
sodium chloride
CLICK to reveal MODEL ANSWER

6. Conduction and convection
WJEC Chemical bonding, structure and properties
Model Question
Draw a diagram to show the covalent bond between two hydrogen atoms?
Model Answer
Some atoms do not lose electrons but share them in order to fill their outer shell.
CLICK to reveal MODEL ANSWER
This mostly happens between non-metals.
It is called covalent bonding.
Hydrogen can covalently bond to chlorine
A hydrogen A chlorine
atom atom
Covalent bonding
Chlorine now has 8 electrons and its outer shell is full
A covalent bond.
Hydrogen has 2 electrons and its outer shell is full
P1.1.3a/P1.1.1

7. Diamond Graphite CLICK to reveal MODEL ANSWER
WJEC Chemical bonding, structure and properties
Diamond and graphite both are giant covalent structures and both made of carbon. They are allotropes of each other..
Diamond
Graphite
Model question
Why is graphite able to conduct electricity?
Model answer
There are free electrons not involved in bonding as only 3 of the 4 outer electrons of each carbon are involved in the bond.
CLICK to reveal MODEL ANSWER
Each carbon is joined to four other carbon atoms.
Diamond is very hard and has a high melting point.
It does not conduct electricity.
Carbon atoms form layers that can slide over each other.
Each carbon atom joined to only three other carbon atoms.
Graphite conducts electricity.

8. CLICK to reveal MODEL ANSWER
WJEC Chemical bonding, structure and properties
Smart materials
Thermochromic
Photochromic
Shape memory alloy
Shape memory polymer
Hydrogel
Change colour with changing temperature
Forehead thermometer
Change colour with changing light intensity
Transitions lenses in glasses
Returns to original shape with heated
Glasses frames
Stents to hold veins open
Returns to original shape when heated
Self repairing car bodies
Absorb water to swell up to 1000 times their size
Artificial muscles
Nappies
CLICK to reveal MODEL ANSWER
Model answer
Thermochromic material is used as it changes colour with a change in temperature to indicate if the food is too hot.
Model question
Name the type of material used for baby feeding spoons and the special property of this type of material

9. WJEC Chemical bonding, structure and properties
How are covalent bonds formed?
What kind of bond forms between metals and non metals?
Why do ionic compounds have high melting and boiling points?
What is an allotrope?
Why can’t diamond conduct electricity?
Why is graphite used in lubricants?
What is the special property of photochromic materials?
Why are hydrogels able to be used in nappies?
Draw the covalent bonding in HCl.
Draw the ionic bonding in CaO.

10. WJEC Chemical bonding, structure and properties - ANSWERS
How are covalent bonds formed?
A covalent bond is formed from a shared pair of electrons.
2. What kind of bond forms between metals and non metals?
Ionic bonds form where the metal donates electrons and the non metal gains electrons.
3. Why do ionic compounds have high melting and boiling points?
The strong electrostatic attraction between the ions means that they have high melting and boiling points.
4. What is an allotrope?
Allotropes are different forms of the same element. Diamond and graphite are allotropes of carbon.
5. Why can’t diamond conduct electricity?
All of the 4 outer electrons in every carbon are involved in bonds and so are not free to move.

11. WJEC Chemical bonding, structure and properties - ANSWERS
6. Why is graphite used in lubricants?
The weak bonds between layers mean that they can easily slide over each other for use in lubricants.
7. What is the special property of photochromic materials?
They change colour with a change in light intensity.
8. Why are hydrogels able to be used in nappies?
They can swell to 1000 times their size.
9. Draw the covalent bonding in HCl
10. Draw the ionic bonding in CaO

12. Final test DTT Booster Students now complete the final test.
Compare this to what they achieved in the diagnostic test.