Metallurgy, Metals, Non-Metals & Alloy RRB PYQ

Sodium is the metal among the given options that reacts vigorously with cold water. When sodium reacts with cold water, it forms sodium hydroxide and hydrogen gas; the reaction is highly exothermic. Unlike sodium, metals such as zinc, iron, and aluminium do not react with cold or hot water; they only react when exposed to steam. Due to its extreme reactivity with both water and the moisture in the air, sodium is traditionally stored submerged in kerosene to prevent accidental combustion.

Sodium metal is highly reactive, especially with water and air, which can cause it to ignite or explode. To prevent this, sodium is stored in kerosene. Kerosene is a non-reactive, oily liquid that creates a barrier, protecting the sodium from moisture and oxygen in the air.

Hydrogen gas is evolved when magnesium and manganese react with very dilute nitric acid. Nitric acid is generally a strong oxidizing agent, which usually oxidizes the hydrogen produced in a reaction into water and itself gets reduced to nitrogen oxides. However, magnesium and manganese are unique because they can react with very dilute nitric acid to liberate hydrogen gas. The chemical equation for magnesium is: Mg + 2HNO3(very dilute) → Mg(NO3)2 + H2↑.

Ductility is the ability of a material to be drawn or plastically deformed without fracture. It is the ability of metals to be drawn into thin wires. Gold is the most ductile metal. Ductility is a permanent strain that accompanies fracture in a tension test. The ductility of the metals increases as the temperature increases.

Mercury is the important metal used in the formation of amalgams. An amalgam is an alloy of mercury with another metal, such as silver, tin, zinc, or gold. Mercury can dissolve many metals and form solid or liquid amalgams depending on the composition. Iron does not readily form an amalgam with mercury, which is why mercury can be stored in iron containers. Dental amalgam traditionally contains mercury combined mainly with silver, tin, and copper.

Copper is the metal that is least reactive with acids among zinc, iron, aluminium, and copper. In the Reactivity Series, metals are ranked based on their ability to lose electrons; copper is positioned below hydrogen, meaning it cannot displace hydrogen from dilute acids like HCl. Zinc, iron, and aluminium are all located above hydrogen in the series, allowing them to react with dilute acids to produce a salt and evolve hydrogen gas. While aluminium is highly reactive, it sometimes appears slow to react initially due to a protective, thin layer of aluminium oxide on its surface.

Lithium is the lightest metal in the periodic table of elements. It is a member of the alkali metal group, which is known for having low densities compared to other metals. Lithium is the third element in the periodic table and has an atomic number of 3. Lithium is highly reactive and flame-retardant, and it should be stored in mineral oil to ensure safety. It is used in the manufacturing of aircraft and certain types of batteries.

Ores are roasted primarily to remove sulphur. Roasting is a metallurgical process involving the heating of ore in the presence of oxygen. This process helps in oxidizing sulphur and other impurities present in the ore to form their respective oxides, which can then be removed.

Bromine is the non-metal that exists as a liquid at room temperature. Bromine is a deep, reddish-brown liquid that evaporates easily into a toxic, pungent-smelling vapor. It belongs to the Halogen family (Group 17) of the periodic table, situated between Chlorine and Iodine. Like other halogens, it is highly reactive and does not occur freely in nature, but rather as colorless soluble crystalline bromide salts.

The most abundant metal in the Earth's crust among the options given is Aluminum. Aluminum comprises approximately 8.23% of the Earth's crust by weight, making it one of the most plentiful elements. It is widely distributed in various minerals and ores, particularly in silicates like feldspar and clay minerals.