Metallurgy, Metals, Non-Metals & Alloy RRB PYQ

Sodium is the metal that is NOT obtained by reduction using carbon. Sodium is usually obtained through the electrolysis of molten sodium chloride (NaCl) in a process called the Downs process.

Total quantity of alloy = 119/35 x 100 = 340. Quantity left in the alloy = (100-35)% = 65%. Quantity of the other elements in the alloy = 65/100 x 340 = 221 gram.

The process of coating steel or iron with a thin layer of zinc to protect it from corrosion is known as galvanization. Zinc acts as a protective barrier to prevent water and oxygen from reaching the steel or iron surface. Even if the zinc layer is damaged, zinc's sacrificial action prevents the underlying steel from corroding. Galvanization is commonly used for steel or iron pipes, outdoor constructions, and metal exposed to harsh environments.

Sodium metal can be easily cut with a knife. Sodium has a body-centered cubic structure. In this structure, the unit cell consists of 8 Na (sodium) atoms at the 8 corners and 1 atom at the center of the cube. Due to this structure, a lot of empty space is present in the unit cell. Also, the Na atom has one valence electron and a large size. The relatively weak metallic bonding in alkali metals makes them soft. Therefore, sodium can be easily cut with a knife. In general, alkali metals are soft metals and can be cut with a knife.

The hardest natural substance is Diamond. Copper, iron, and graphite are all relatively soft metals compared to diamond. Diamond is a form of carbon where the atoms are arranged in a very strong and rigid structure. This structure makes it extremely difficult to scratch or break diamond.

Free state or combined state are the states of metals. Metals can exist in two states: Free state: In this state, metals are found in their pure, elemental form, without combining with other elements. Examples include gold, platinum, and sometimes copper, which can be found in their free state in nature. Combined state: In this state, metals are combined with other elements, typically forming compounds. Most metals are found in nature in this state as ores, which are minerals containing metals chemically combined with other elements, such as oxygen or sulfur.

When a metal reacts with sodium hydroxide (NaOH), hydrogen gas is usually emitted. This reaction is a type of single displacement reaction where the metal displaces hydrogen from the hydroxide. Certain amphoteric metals such as aluminium and zinc react with sodium hydroxide to form the corresponding sodium salt and release hydrogen gas. 2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2↑; Zn + 2NaOH → Na2ZnO2 + H2↑.

If Metal A displaces Metal B from its solution, it indicates that Metal A is more reactive than Metal B. Reactive elements have a tendency to displace less reactive elements in chemical reactions. This reactivity arises from the ability of reactive metals to readily lose electrons, aiming to achieve a stable electronic configuration by reducing other elements and oxidising themselves. Reactive metals are typically positioned at the top of the reactivity series.

Potassium is a highly reactive alkali metal. When it comes in contact with cold water, it reacts violently, releasing hydrogen gas (H2) and forming potassium hydroxide (KOH). This reaction is often accompanied by a flame due to the ignition of the hydrogen gas. Aluminium, zinc, and iron are less reactive metals. They may react with steam or very hot water, but their reaction with cold water is not vigorous. Aluminium forms a thin oxide layer that passivates the surface, hindering further reaction with cold water. Zinc and iron react slowly with cold water, producing hydrogen gas at a much slower rate.

Statement A is incorrect because the modern periodic table has 118 elements, not 124. Among these, around 92 are metals, 20 are non-metals, and 6 are metalloids. Statement B is true, as every ore is a mineral, but not all minerals are ores. An ore is a type of mineral that contains a valuable substance that can be extracted economically.