Metals and Their Uses Flashcards
Where are metals usually found?
In the Earth’s crust
What is an ore?
A rock containing enough metal/metal compound to make it worth extracting the metal
How are some metals low in the reactivity series found?
As pure or nearly pure metals. Little extraction is needed as they can be extracted through physical methods.
How can metals be extracted from compounds?
Through displacement reactions using a more reactive element
How are metals that are less reactive than carbon extracted from their oxides?
They are heated with carbon and a reduction reaction occurs as the carbon removes the oxygen (forming carbon dioxide), leaving just the metal. This method is used comercially if possible
How is iron oxide reduced to make a purer form of iron?
In a blast furnace at high temperatures using carbon.
What do many of the ores used to produce iron contain?
Iron (II) oxide
What percentage of iron does the iron from a blast furnace contain?
96% iron - this is known as cast iron
What are the properties of cast iron?
The impurities make it hard and brittle so it has few uses
What are the properties of pure iron?
Soft - too soft for many uses
What are steels?
Alloys of iron - mixtures of iron with carbon and other elements
What is most iron used to make?
Steels
What are the properties of low-carbon steels compared to high-carbon steels?
Easily shaped vs. hard
Stainless steel contains …? This means that it…?
Contains larger quanities of other metals. This means that it resists corrosion.
What do steels contain?
Carefully controlled quanities of carbon and other elements. This gives them specific properties for specific uses.
What are the properties of aluminium?
- Low density compared to other hard metals
- Even though it’s high in the reactivity series it is resistant to corrosion
- Pure aluminium is not very strong, but its alloys are stronger and harder.
What are the properties of titanium?
- Low density compared to other hard metals
- Very strong
- Resistant to corrosion
How is aluminium extracted?
- More reactive than carbon so cannot be reduced.
- Has to be extracted through the electrolysis of molten aluminium oxide.
- This requires high temperatures and lots of energy, making aluminium expensive
How is titanium extracted?
- Can be reduced using carbon, but reacts with it making the metal brittle.
- Instead it is extracted from its ore by a process that involves several stages and large amounts of energy.
- This makes titanium expensive
How is most copper extracted?
From copper rich ores by smelting - this means heating the ore strongly in a furnace. This produces impure copepr
How is copper purified?
Using electrolysis
What are the disadvantages of extracting copper using smelting/electrolysis?
- It requires huge amounts of heating and electricity (lots of energy)
- Copper-rich ores are a limitted resource
Describe the new ways scientists are developing to extract copper.
- These new methods work by extracting copper from low-grade ores and have less environmental impact than smelting
- Phytomining uses plants to absorb copper compounds from the ground. The plants are then burned to produce ash from which the copper can be extracted,
- Bioleaching uses bacteria to produce solutions containing certain copper compounds
How else can copper be obtained?
From solutions of copper salts/compounds by reacting with a more reactive metal to displace the copper.
Copper can also be extracted from solutions of copper compounds by electrolysis.
What are the three main ways of extracting copper from its compounds? (Plus 2 other ways)
- Smelting
- Electrolysis
- Displacement
As well as phytomining and bioleaching
What are the main properties of the transition metals?
- Good conductors of heat and electricity
- Strong but can be hammered or bent into shape
- Less reactive than alkali and alkali earth metals
- Most have high melting and boiling points (higher than Group 1)
- Form coloured compounds
- High densities
What do the properties of transition metals make them useful for?
Building and making things
Complete the sentence:
Most of the ___ we use are ___
Most of the metals we use are alloys
What are the properties of copper and what are its uses?
- Very good conductor of heat
- Does not react with water
- Can be bent but is hard enough to keep its shape
These properties make it useful for making tanks in water/heating systems.
- Very good conductor of electricity as well.
Can also be used for electrical wiring (bendy)
What are the uses of iron, gold, aluminium, and copper alloys?
- Iron is made into steels
- Gold is used in jewlery as an alloy
- Most of the aluminium used for buildings and aircraft is alloyed
- Copper alloys include bronze and brass (sculptures etc. + instruments!)
What are the disadvantages of mining for metal ores?
- Involves digging up and processing large amounts of rock
- Produces large amounts of waste materials
- Effects large areas of the environment
What are the advantages of recycling?
- Saves the energy needed to extract the metal from its ore
- Saves resources because less ore needs to be mined
- Less fossil fuel is needed to provide the energy to extract the metal from its ore
What are the benefits of using metals in construction?
- Strong
- Can be bent into shape
- Can be made into flexible wires
- Good electrical conductors
What are the drawbacks of using metals in construction?
- Obtaining metals from ores causes pollution
- Also uses up limited resources
- More expensive than other materials such as concrete
- Iron and steel can rust
