C4 complete Flashcards
What is an alloy?
Alloy is a mixture of a metal and another element.
What are an alloys properties and uses?
Properties are: alloys are harder than pure metals.
Bronze is an alloy of copper and tin.
Steel is an alloy of iron and carbon.
What is a composite?
Composites are made of different materials.
What are a ceramics properties and uses?
Properties still and brittle, but clay and glass can be made out of ceramics
What are a polymers properties and uses?
Hint: making polymers synthetically…
Making polymers synthetically, involves a high pressure and a catalyst normally
The forces between chains influence the properties of a polymer
Polymers are held together by covalent bonds and intermollecular forces
What are a composites properties and uses?
Properties in definition, fibreglass can be made by composites (one material embedded in another).
What are the two different types of polymerisation?
Addition and Condensation
Giant covalent structures contain many covalent bonds
What are giant covalent structures? (3 points)
- Strong covalent bonds
- High melting and boiling points
- Not conductive
- Tend to be insoluble in water.
Diamond properties (2)
- Sparkly and colourless.
- In a giant covalent structure, each carbon atom forming four covalent bonds making it rigid and hard.
- Doesn’t conduct electricity.
Graphite properties (3)
- Black, opaque but still a bit shiny.
- 3 covalent bonds creating sheets of carbon atoms which are free to slide weak forces between layers.
- High melting point - covalent bonds need loads of energy to break.
- Conductive
Graphene properties (2)
- Single sheet of graphite
- Conductive
- 3 covalent bonds very strong because it is only 1 layer.
What is a polymer?
Polymers are long molecules formed when lots of small molecules called monomers join together. This is called polymerisation.
How do you make an addition polymer?
Addition polymers have carbon double bond functional group, double bonds break to from polymer chains.
How do you make a condensation polymer?
Condensation polymerisation usually involves two different types of monomers containing different functional groups. (Di)
Monomers react together and bonds form between them making polymer chains.
Name an addition and a condensation polymer.
A=Polythene
B=Polyester
Name a naturally occurring polymer.
Explain why it is.
DNA
It contains two strands made of monomers called nucleotides that bond together in a polymerisation reaction.
How are polymers held together?
Polymers are held together by strong covalent bonds and intermolecular forces between the chains.
What influences the properties of a polymer?
The forces between the chains and structure.
What is the difference between a low density and high density polymer? And give a use for each.
Low density: space between polymer chains, so forces between chains are relatively weak so flexible used for bags and bottles.
High density: chains packed closely together so forces between them are stronger. Therefore still so it can be used in water tanks and drainpipes.
Brittleness is what?
When something break when being hit by a sudden force.
Name an advantage and disadvantage of a polymer.
adv. polymers are really adaptable
dis. Usually degrade over time.
Name an advantage and disadvantage of a ceramic.
adv. strong and insulator of heat and electricity.
dis. poor shock resistance.
Name an advantage and disadvantage of a metal.
adv. metals are good conductors of heat and electricity. Malleable
dis. Deformities
Name an advantage and disadvantage of a composite.
adv. Can be designed to match a specific purpose
dis. expensive
What does malleable mean?
Can be pressed into shape without breaking.
OILRIG
Oxidation is loss (of electrons)
Reduction is gain (of electrons)
What is oxidation?
Oxidation is the addition of oxygen to an element or compound
What is needed for iron to corrode? (2 things)
Air
Water
Name the two main ways for corrosion prevention. (2 things) And what is one way you have to do to prevent corrosion.
Create a barrier between the metal and water+oxygen.
Painting
Oiling/greasing
What is required when extracting energy?
Where does the energy come from and how is this a problem.
Energy is required and that comes from burning fossils fuels which are a finite resource. +Burning them causes pollution.
What is the point of life cycle assessments?
They show the total environmental costs.
Name four things that are taken into consideration when wanting to carry out a LCA.
Choice of material (is it a non-renewable resource)
Manufacture (how much energy used + pollution caused)
Product use (will it be harmful to the environment)
Disposal
Nanoparticles are very tiny and are often given in what size?
Nanometres (nm)
What form are nanoparticles given in?
Standard form usually.
Name the important feature of nanoparticles.
They have a large surface area : volume ratio.
What are fullerenes? What shape were they.
Fullerenes are nanoparticles of carbon.
They’re large molecules shaped like hollow balls and tubes.
What can fullerenes form?
And name two things about what they can form.
Form nanotubes which are tiny carbon cylinders.
They have delocalised electrons so they can conduct and they also have a high tensile strength.
Name two things nanoparticles are modified to be used in.
Cosmetics like sun creams and deodorants.
Effects of nanoparticles on health aren’t fully understood.
Why? (2)
Nanoparticles are so small they can get into cells deep within the body. Also they have a high surface area so they could react in unknown ways leading to unexpected side effects.