Q1: Which of the following metals can not be hot worked at room temperature ?

ANS:B - Nickel

Nickel is a metallic element with the symbol Ni and atomic number 28. It belongs to the transition metal group on the periodic table. Here's some information about nickel:

1. Properties: Nickel is a silvery-white metal with a slight golden tinge. It is malleable, ductile, and has good corrosion resistance, especially when plated. It is ferromagnetic at room temperature, meaning it is attracted to magnets.
2. Applications: Nickel has numerous industrial applications. It is commonly used in the production of stainless steel, where it enhances the corrosion resistance and strength of the alloy. Nickel is also used in various other alloys, including those used in electrical heating elements, coinage, batteries, and special-purpose alloys in electronics and aerospace applications. Additionally, nickel is used as a catalyst in certain chemical reactions.
3. Alloys: Nickel is frequently alloyed with other metals to create materials with specific properties. For example, nickel-based superalloys are used in jet engines and gas turbines due to their exceptional heat resistance and strength at high temperatures. Nickel-copper alloys, such as Monel and Inconel, are known for their corrosion resistance and are used in marine engineering and chemical processing.
4. Mining and Production: Nickel is typically obtained from nickel sulfide ores or lateritic ores. The ores are processed to extract nickel metal through various techniques, including smelting and hydrometallurgical processes.