A thin shield
Protective oxide layer.
Left in the open
A piece of aluminium is left in the open air at ordinary temperature.
What happens to its surface?
What this lesson covers
The idea
At ordinary temperature the surfaces of metals such as magnesium, aluminium, zinc and lead are covered with a thin oxide layer that prevents the metal from further oxidation.
Left in the open
A piece of aluminium is left in the open air at ordinary temperature.
What happens to its surface?
- A thin oxide layer covers it
- It burns with a flame
- It turns into a liquid
Zoom in on the surface
Press Next step.
A skin that protects
Magnesium, aluminium, zinc and lead get a thin layer of oxide on their surface in air at ordinary temperature. This layer protects them: it prevents the metal from oxidising further.
At ordinary temperature the surfaces of metals such as magnesium, aluminium, zinc and lead are covered with a thin oxide layer that prevents the metal from further oxidation.
Notes
A thin oxide layer on Mg, Al, Zn, Pb at ordinary temperature prevents further oxidation.
Check yourself
The thin oxide layer on aluminium ...
Which of these has a thin oxide layer at ordinary temperature?
The oxide layer on magnesium is ...
- makes the metal burn. The oxide layer protects the metal from further oxidation; it does not make it burn.
- prevents the metal from further oxidation — correct. Yes!
- changes the metal to a gas. The layer is a thin coat of oxide, which protects the metal.
- Gold. Gold does not react with oxygen even at high temperatures, so it has no oxide layer.
- Silver. Silver does not react with oxygen even at high temperatures, so it has no oxide layer.
- Zinc — correct. Yes!
- thin and protective — correct. Yes!
- thick and harmful. The book calls it a thin layer that protects the metal.
- absent in air. The book says magnesium's surface is covered with a thin oxide layer.