Using Resources Flashcards
What is a ceramic?
A non-metal solid with a high melting point that isn’t made from carbon-based compounds.
What are examples of ceramics?
Clay and glass.
How is soda-lime glass made?
By heating a mixture of limestone, sand and sodium carbonate (soda) until it melts. The cooled mixture is glass.
What is borosilicate glass made of?
Sand and boron trioxide.
What is an advantage of using borosilicate glass compared to soda-lime glass?
It has a higher melting point than soda-lime glass.
What are composites?
Composites are made of one material embedded in another. Fibres or fragments of a material (known as the reinforcement) are surrounded by a matrix acting as a binder.
What are examples of composites?
Fibreglass, carbon fibre, concrete and wood.
What determines the properties of polymers?
Several things can influence the properties of a polymer such as how it’s made and what it’s made from. The monomers that a polymer is made from determine the type of bonds that form between the polymer chains. These weak bonds between the different molecule chains determine the properties of the polymer.
What are the properties of ceramics?
Ceramics include glass and clay ceramics such as porcelain and bricks. They’re insulators of heat and electricity, brittle and stiff.
What are the properties of polymers?
Polymers are insulators of heat and electricity, they can be flexible and are easily moulded. Polymers have many applications including in clothing and insulators in electrical items.
What are the properties of composites?
The properties of composites depend on the matrix/binder and the reinforcement used to make them, so they have many different uses.
What are the properties and uses of metals?
Metals are malleable, good conductors of heat and electricity, ductile, shiny and stiff. Metals have many uses, including in electrical wires, car body-work and cutlery.
What are ways to prevent corrosion?
- Painting/coating with plastic - This acts as a barrier
- Electroplating - This uses electrolysis to reduce metal ions onto an iron electrode. It can be used to coat the iron with a layer of a different metal that won’t be corroded away.
- Oiling/greasing - This has to be used when moving parts are involved, like on bike chains.
- Sacrificial method - This involves pacing a more reactive metal such as zinc or magnesium with iron. Water and oxygen then react with the sacrificial metal instead of with the iron.
- Combination of several methods (e.g. spraying material with zinc, initially protective, but when scratched, becomes a sacrificial metal.
What is corrosion?
Where metals react with substances in their environment (e.g. water and oxygen) and are gradually destroyed.
What is included in the process of treating fresh water to make it safe for human consumption?
1) Filtration - a wire mesh screens out large twigs etc., and then gravel and sand beds filter out any other solid bits.
2) Sterilisation - the water is sterilised to kill any harmful bacteria or microbes. This can be done by bubbling chlorine gas through it or by using ozone or ultraviolet light.
