Question

Galvanising means covering steel with a thin layer of ______.
1. Chromium
2. Zinc
3. Aluminium
4. Nickel

Answer 1

Correct Answer - Option 2 : Zinc

The correct answer is zinc.

• Galvanization is the process of applying a protective zinc coating to steel or iron.
• The Zinc layer is applied to prevent rusting. 
• The most common method is hot-dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
• Galvanizing protects from rust in a number of ways:
  • It forms a barrier that prevents corrosive substances from reaching the underlying steel or iron.
  • The zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.
  • The zinc protects its base metal by corroding before iron.
  • The zinc surface reacts with the atmosphere to form a compact, adherent patina that is insoluble in rainwater.

• Chromium is a member of the transition metal group in the periodic table and it is used as an alloy.
• Aluminium metal extraction is mainly from bauxite ore by the "electrolysis method"

Element	Symbol	Atomic number
Chromium	Cr	24
Aluminium	Al	13
Nickel	Ni	28