Correct Option
The correct option is (a).
Explanation
Electroplating is the process of depositing a layer of a desired metal onto another material by means of electricity. Chromium plating is a common application of this process, utilized primarily to enhance the appearance and durability of objects made from cheaper or less resistant metals like iron or steel.
Statement-wise Analysis
- Statement 1 is Correct: Chromium has a highly reflective, shiny appearance. This aesthetic quality makes it ideal for decorative parts on cars, bath fittings, and kitchen appliances.
- Statement 2 is Correct: Chromium is highly resistant to corrosion. It does not rust easily when exposed to moisture and air, thereby protecting the underlying metal (usually iron or steel) from oxidation and degradation.
- Statement 3 is Incorrect: Chromium is a very hard metal. It is resistant to scratches and wear, which is a primary reason it is used on surfaces subject to frequent handling or abrasion, such as taps and car handles.
- Statement 4 is Incorrect: Chromium is an expensive metal, significantly more costly than iron or steel. Because of the high cost, it is not economically feasible to make the entire object out of chromium. Instead, a thin layer of chromium is deposited over a cheaper base metal.
Key Takeaway: Chromium plating is employed because chromium is shiny, corrosion-resistant, and scratch-resistant (hard). However, due to its high cost, it is only used as a thin surface coating rather than the structural material.