Metallurgy, Metals, Non-Metals & Alloy RRB PYQ

When sodium metal reacts with water, it produces hydrogen gas and sodium hydroxide solution. The reaction is highly exothermic, meaning it releases heat, and the hydrogen gas formed can ignite, producing a yellow flame. The balanced chemical equation for this reaction is: 2Na + 2H2O → 2NaOH + H2. This is a common demonstration to show the reactivity of sodium, an alkali metal, with water.

Metals can displace each other according to their reactivity. This is based on the reactivity series, which ranks metals from highest to lowest reactivity. A more reactive metal can displace a less reactive metal from its compound in a single displacement reaction.

The incorrect statement is that lead and mercury are comparatively good conductors of heat. Metals are good conductors of heat; most metals like copper and aluminum transfer heat efficiently. Metals can be drawn into thin wires — this property is called ductility (e.g., copper wires). Metals have a shiny surface in their pure state.

Corrosion is an electrochemical process that causes the deterioration of metals due to their reaction with oxygen, water, and other environmental factors. Over time, corrosion leads to the formation of rust on iron and other metals, weakening their structure and appearance.

The elements such as neptunium and plutonium were found in Pitchblende. Pitchblende is a radioactive mineral and the primary ore of uranium. Elements like neptunium and plutonium are not naturally abundant but are formed as by-products in nuclear reactors or during the decay of uranium found in pitchblende. Plutonium-239 is produced by neutron capture in uranium-238, which is abundant in pitchblende.

Statement I: When copper powder is heated, it reacts with oxygen to form black copper(II) oxide (CuO), an oxidation reaction. Statement II: When hydrogen gas is passed over the heated copper(II) oxide (CuO), it reduces the black CuO to brown copper metal (Cu) and forms water (H2O), a reduction reaction.

Silicon (Si), a non-metallic element belonging to the carbon family, has an octahedral crystalline structure. Due to its high reactivity, pure silicon is not found in nature. Instead, it combines with other elements or oxygen to form silica, which is abundant in rocks, sand, clays, and soils. Additionally, the long-chain compounds formed by silicon exhibit significant reactivity.

Nickel and chromium are mixed with iron to get stainless steel. Stainless steel is primarily made by mixing iron with chromium (Cr) and nickel (Ni). Chromium provides corrosion resistance, while nickel enhances strength and durability. Some stainless steel grades may also contain small amounts of carbon, molybdenum, and manganese to improve specific properties.

Non-metal oxides are generally acidic in nature. They react with bases to form salt and water. For example, carbon dioxide reacts with calcium hydroxide to form calcium carbonate and water: CO2 + Ca(OH)2 → CaCO3 + H2O. Some non-metal oxides, such as carbon monoxide (CO) and nitric oxide (NO), are neutral; therefore, 'acidic' is the usual or general property rather than an absolute rule.

Sodium, Potassium, and Lithium are alkali metals and are considered alkaline elements. These metals belong to Group 1 of the periodic table, and they have a tendency to form alkaline solutions when combined with water. Sulphur, on the other hand, is a non-metal and is not alkaline; it is generally classified as a non-metallic, acidic element.