Year 10, Test 1 Flashcards
How much plastic is produced each year?
Approximately 300 million tonnes
This figure highlights the global scale of plastic production.
What is a key characteristic of plastic production?
Relatively inexpensive to produce
This affordability contributes to widespread use in various industries.
What is a notable property of plastic?
Very versatile
Plastic can be molded into different shapes and used in a variety of applications.
What are polymers mostly made of?
Mostly synthetic materials
Polymers are large molecules made up of repeating structural units.
From what resources are most synthetic polymers derived?
Finite resources such as coal, natural gases, and crude oil
These resources are non-renewable and contribute to environmental concerns.
What is an alternative to synthetic polymers?
More renewable and sustainable materials
These alternatives aim to reduce dependency on finite resources.
What is a key characteristic of thermoplastics?
Can be repeatedly heated and remoulded
Thermoplastics can be reshaped multiple times without significant degradation.
What is a disadvantage of thermoplastics?
Not suitable for use in areas of heat or UV sensitivity
This limits their application in certain environments.
What is one advantage of thermoplastics regarding their surface?
Good surface finish
This makes them aesthetically pleasing for various applications.
Can thermoplastics be recycled?
Yes
Recycling thermoplastics helps reduce waste and environmental impact.
What phenomenon occurs when thermoplastics are reheated?
Plastic memory
This means they attempt to return to their original shape when reheated.
What is melamine formaldehyde known for?
Good insulation and heat resistance
It is a type of thermoset plastic.
What are the key properties of urea formaldehyde?
High electrical insulation, good heat resistance
Urea formaldehyde is another type of thermoset.
What is polyester resin primarily used for?
Bonding agent in glass and reinforced plastics
It is a versatile thermoset plastic.
What is a key advantage of thermosets?
Able to withstand high temperatures
This makes them suitable for demanding applications.
What happens to thermosets when they are solid?
Waterproof
This property enhances their utility in various environments.
What is one of the properties of thermosets regarding electrical insulation?
Good electrical insulator
This makes thermosets useful in electrical applications.
Can thermosets be remoulded?
No
Once set, thermosets cannot be reshaped.
What is extrusion in plastic manufacturing?
Creating objects with a cross-section profile
This process is used for making continuous shapes.
What does injection moulding involve?
Injecting heated plastic into a mould
This allows for the production of complex shapes.
What is vacuum forming?
Sheet of softened plastic forced onto a mould
This technique is often used for creating packaging and containers.
What are ferrous metals?
Metals that can rust and contain iron
Ferrous metals are prone to corrosion when exposed to moisture.
What is rust?
A compound called iron oxide formed when iron and oxygen react in the presence of moisture or organic water
Rusting is a common issue with ferrous metals.
What is a key property of ferrous metals?
They are magnetic
This magnetic property is due to the presence of iron.
What protects ferrous metals from rusting?
Zinc coating
Zinc acts as a sacrificial anode to prevent rust.
What are non-ferrous metals?
Metals that do not contain iron
Non-ferrous metals are less prone to rust.
How do non-ferrous metals compare in cost to ferrous metals?
More expensive
Non-ferrous metals typically have higher material costs.
What are some properties of non-ferrous metals?
- Lightweight
- Conductive
- Ductile
- Malleable
These properties make non-ferrous metals suitable for various applications.
What is the process of extracting iron from iron ore called?
Smelting
Smelting involves using a blast furnace to extract iron.
What temperature can a blast furnace reach during the smelting process?
1,700°C
This high temperature is necessary for melting iron.
At what temperature does iron melt?
1538°C
Iron liquefies and sinks to the bottom of the furnace when it reaches this temperature.
What is the term used for molten iron that has been extracted from the blast furnace?
Pig iron
Pig iron is the initial product of smelting iron ore.
What is a characteristic of pig iron?
Very high carbon content
This high carbon content makes pig iron brittle.
What is done to pig iron to produce steel?
Some carbon and impurities are removed
This process is essential for producing steel from pig iron.
What is the main source of aluminum?
Bauxite ore
Bauxite is the primary ore used for aluminum extraction.
What is a ferrous metal?
A metal that contains iron and will rust
Ferrous metals are magnetic and include steel.
Name a key characteristic of ferrous metals.
They will rust
Rusting occurs due to the oxidation of iron.
What is the primary element in ferrous metals?
Iron
Iron is the main component of ferrous metals.
What type of carbon content is associated with mild steel?
Low carbon content
Mild steel typically contains about 0.05% to 0.25% carbon.
What are non-ferrous metals?
Metals that do not contain iron
Non-ferrous metals are resistant to rust.
List three examples of non-ferrous metals.
- Aluminium
- Copper
- Gold
Other examples include silver, platinum, palladium, and titanium.
What is an alloy?
A mixture of two or more metals
Alloys have different properties than their component metals.
Name two examples of alloys.
- Brass
- Stainless steel
Alloys are created to enhance properties such as strength and corrosion resistance.
True or False: Non-ferrous metals will rust.
False
Non-ferrous metals do not contain iron, making them resistant to rust.
Fill in the blank: _______ is a common non-ferrous metal used in electrical wiring.
Copper
Copper is highly conductive and widely used in electrical applications.
What is newly cut wood called?
Green timber
Green timber contains about 50% water.
What percentage of water does green timber contain?
50%
This high moisture content makes it harder to work with.
Is green timber harder or easier to work with compared to seasoned wood?
Harder to work with
The high moisture content contributes to this difficulty.
What is the recommended moisture content for exterior use of green timber?
20%
This level of moisture is generally acceptable for outdoor applications.
What is the recommended moisture content for interior use of green timber?
Under 10%
Lower moisture is preferred for indoor applications to prevent issues such as warping.
What is newly cut wood called?
Green timber
Green timber contains about 50% water.
What percentage of water does green timber contain?
50%
This high moisture content makes it harder to work with.
Is green timber harder or easier to work with compared to seasoned wood?
Harder to work with
The high moisture content contributes to this difficulty.
What is the recommended moisture content for exterior use of green timber?
20%
This level of moisture is generally acceptable for outdoor applications.
What is the recommended moisture content for interior use of green timber?
Under 10%
Lower moisture is preferred for indoor applications to prevent issues such as warping.
