Are the melting and boiling points of simple molecular structures low or high?
Low
Are the forces weak or strong in simple molecular structures?
Weak
Are simple molecular structures made from non-metal or metal elements?
Non-metals
What are giant ionic structures made from?
Ions
Are the ions in giant ionic structures held together by strong or weak bonds?
Weak
Are the melting and boiling points of giant ionic structures or salts high or low?
High
Is a lot of energy needed to break the bonds in giant ionic structures?
Yes
Are the ions arranged regularly or irregularly in a giant ionic structure?
Regularly
Why do giant ionic structure only conduct electricity in a solution or if molten?
The ions are free to move.
Give an example of a giant molecular structure
Diamond
What kind of bonds are in giant molecular structures?
Strong covalent bonds
Is a lot of energy needed to separate the carbon atoms in a diamond?
Yes
Does diamond have a high boiling and melting point?
Yes
Does diamond dissolve in water?
No
Name another giant molecular structure
Graphite
How are the layers of graphite held together?
With strong forces of attraction
Giant metallic structures have a) negative or b) positive electrons in a sea?
Negative
How do the charges on the metal ions and electrons hold the ions together?
There is a strong attraction between the positive metal ions and the negative electrons.
Give three properties of thermo-setting polymers
Solid, hard, rigid
Do thermo-setting polymers have cross links the hold the chains together?
Yes
Do thermo-softening polymers have cross links between the chains?
No
Give a property of a thermo-setting polymer and explain why it works
Easy to mould because the forces between the chains are easy to overcome
How is low-density polyethene made?
By heating ethene at 200’c under high pressure
Give a property of low density polyethene
Flexible
Give uses of low density polyethene
Bags and bottles
How is high density poly ethene made?
With a lower temperature and pressure in the presence of a catalyst
Give a property of high density polyethene
Rigid
Give a use of high density polyethene
Water tanks
What is an alloy
Two metals mixed to have the best possible properties
What are nano particles?
Very small particles
What are fullerenes?
Molecules of carbon arranged in hexagonal rings.
What kind of bonding is involved in carbon atoms when making carbon nanotubes?
Covalent
Do nano particles have a small or large surface area to volume ratio?
Large