Metals Flashcards
Which metals and metal compounds are found in the Earth’s crust?
The Earth’s crust contains metals and metal compounds such as gold, iron oxide and aluminium oxide, but when found in the Earth these are often mixed with other substances.
When are metals produced?
Metals are produced when metal oxides are reduced (have their oxygen removed).
How are less reactive metals extracted?
Iron and other less reactive metals may be extracted by reaction with carbon or carbon monoxide.
How are highly reactive methods extracted?
Electrolysis
What happens to Gold because it is so unreactive?
It is unreactive, so it is found as a native metal and not as a compound. It does not need to be chemically extracted from its ore, but chemical reactions may be needed to remove other elements that might contaminate the metal.
What do transition metals have in common?
They are metals. They are good conductors of heat and electricity. They can be hammered or bent into shape easily.
What is helpful about transition metals?
The transition metals are useful as construction materials. They are also useful for making objects that need to let electricity or heat travel through them easily.
What is the name of the reaction where oxygen is removed?
Reduction Reactions.
How is iron extracted from it’s ore?
Iron is extracted from iron ore in a huge container called a blast furnace. Iron ores such as haematite contain iron oxide. The oxygen must be removed from the iron oxide to leave the iron behind. This is an example of a reduction reaction.
What are some advantages of copper?
Copper is soft and easily bent and so is a good conductor of electricity, which makes it useful for wiring. Copper is also a good conductor of heat and it does not react with water. This makes it useful for plumbing, and making pipes and tanks.
How is copper extracted from it’s ore?
Copper can be extracted from it’s ores by heating them in a furnace, a process called smelting. The copper is then purified using a process called electrolysis.
What happens during electrolysis?
Electricity is passed through solutions containing copper compounds, such as copper sulphate. During electrolysis, positively charged copper ions move towards the negative electrode and are deposited as copper metal.
What is phytomining?
Some plants absorb copper compounds through their roots. They concentrate these compounds as a result of this. The plants can be burned to produce an ash that contains the copper compounds. This method of extraction is called phytomining.
What is bioleaching?
Some bacteria absorb copper compounds. They then produce solutions called leachates, which contain copper compounds. This method of extraction is called bioleaching.
How can copper be extracted from scrap iron?
Copper can also be extracted from solutions of copper salts using scrap iron. Iron is more reactive than copper, so it can displace copper from copper salts. For example: iron + copper sulphate → iron sulphate + copper
What do aluminium and titanium have in common?
They both have a low density, meaning that they are both lightweight for their size.
Which two properties of aluminium and titanium make them useful?
Aluminium and titanium have a very thin layer of their oxides on the surface, which stops air and water getting to the metal, so they resist corrosion. They also have a low density. These properties make the two metals very useful.
What is aluminium used for?
Aluminium is used for aircraft, trains, overhead power cables, saucepans and cooking foil.
What is titanium used for?
Titanium is used for fighter aircraft, artificial hip joints and pipes in nuclear power stations.
How are aluminium and titanium different to iron?
Unlike iron, aluminium and titanium cannot be extracted from their oxides by reduction with carbon. Existing methods are expensive because: The processes have many stages. Large amounts of energy are needed.
How is recycling aluminium better than extracting it from it’s ore?
Aluminium is extensively recycled because less energy is needed to produce recycled aluminium than to extract aluminium from its ore.
What is an alloy?
A mixture of two or more elements, where at least one element is a metal, is called an alloy.
What are the properties of alloys?
Alloys contain atoms of different sizes, which distort the regular arrangements of atoms. This makes it more difficult for the layers to slide over each other, so alloys are harder than the pure metal.
What are the properties of pure iron?
Pure iron is soft and easily shaped because its atoms are arranged in a regular way that lets layers of atoms slide over each other. Pure iron is too soft for many uses.
