Aluminium surfaces are often 'anodized'. This means the deposition of a layer of a) chromium oxide b) aluminium oxide c) nickel oxide d) zinc oxide
- Aa) chromium oxide
- Bb) aluminium oxideCorrect
- Cc) nickel oxide
- Dd) zinc oxide
Explanation
Anodizing is an electrochemical process used to increase the thickness of the natural oxide layer on the surface of metal parts. In the case of aluminium, the process involves passing an electric current through an electrolytic solution where the aluminium object acts as the anode. This causes the surface of the aluminium to react with oxygen, forming a durable and corrosion resistant layer of aluminium oxide. This protective coating helps prevent further oxidation and allows the surface to be dyed in various colors. Therefore, anodizing aluminium specifically refers to the deposition of a layer of aluminium oxide.
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