Properties of metals
Why can metals be hammered into different shapes (malleable)?
Because of their positive ions arranged in layers that don’t break the overall bond when sliding over one another
Explain why the main body of cooking pots is made from metal
Because metals are good conductors of heat, allowing heat from the cooker to pass through them easily and go into the food.
State the meaning of the term alloy and why they are more useful than pure metals.
Alloys are a mixture of a metal with another element, making them harder, stronger, and more resistant to corrosion.
What do metals react with to create a metal hydroxide and hydrogen? Provide an example
Cold water/steam
Sodium + water → sodium hydroxide + hydrogen
Which metal would be suitable for making aircraft bodies, food containers, and overhead power cables? Explain why
Aluminium, thanks to its low density, corrosion resistance, and high conductivity, performs well over long periods and makes it ideal for storing food and drinks, as it will not affect the taste.
State what brass is made from, why, and how it is used.
Brass is made by using Copper and Zinc, making it resistant to corrosion while having an attractive golden colour, allowing it to be used to improve the looks of objects that would come into contact with the weather.
Magnesium reacts with hydrochloric acid. Complete the equations:
Magnesium + Hydrochloric Acid -->
Mg (s) + 2HCl (aq) -->
Magnesium + Hydrochloric Acid --> magnesium chloride + hydrogen
Mg (s) + 2HCl (aq) --> MgCl2 (aq) + H2 (g)
State the property of aluminum that prevents overhead cables from dropping or breaking under their own weight.
Steel is the name for a group of alloys made with iron. Explain why steel is classified as a mixture rather than a chemical compound
The elements in steel are not chemically bonded together, meaning that by changing what you mix with the iron, you can create a variety of different steels with different properties.
Name the type of bonding that causes metals to have high melting and boiling points, and explain why this occurs.
Metallic bonding creates a strong electrostatic attraction between the ions and the delocalised electrons, requiring lots of energy to break the bonds between them, causing such high melting and boiling points.
How can electrolysis in Copper be used in wires?
By making Copper in a very pure form that increases efficiency and helps increase safety by preventing overheating in the wires.
Stainless steel is an alloy that includes iron mixed with carbon and other metals like chromium and nickel. Explain why stainless steel is used in cutlery.
Chromium protects the iron within the alloy from rusting, making it resistant to corrosion, and it is hard.
Copper can be stretched into wires that conduct electricity. Name the property of metals that means they can be stretched into wires, and describe why metals are good conductors.
Ductility and because they have a sea of delocalised electrons that move freely, allowing conductivity.
Copper is widely used for electrical wiring and for making cooking pans. Explain why copper is used for water pipes rather than iron.
Copper is unreactive and does not react with water, making it corrosion-resistant, whereas iron reacts with water and oxygen to form rust (corrosion).
In terms of their particle arrangement, describe why pure metals are softer and more malleable than alloys.
The layers of a pure metal's atoms can slide easily past each other, while alloys contain atoms of different sizes, and so cannot slide over each other, making them stronger and harder.