Metallurgy, Metals, Non-Metals & Alloy RRB PYQ

Mica is a non-metallic mineral, unlike metals such as silver and lead, which are metallic minerals. Non-metallic minerals like mica are used in various industries, especially in electrical and insulation applications, because of their properties. Other examples of non-metallic minerals include limestone, gypsum, and coal, which do not contain metal content in their natural state.

Metals are electropositive because they tend to lose electrons when forming bonds, leading to a positive charge. This is a characteristic of metals, differentiating them from non-metals, which gain electrons and are thus electronegative.

Magnesium (Mg) is more active towards dilute hydrochloric acid. Magnesium is the most reactive among the mentioned metals and reacts vigorously with dilute hydrochloric acid, releasing hydrogen gas. Aluminum reacts with hydrochloric acid but forms a protective oxide layer that slows down the reaction. Zinc reacts moderately with hydrochloric acid.

Aluminium does not react with either cold or hot water because its surface is protected by a thin, stable layer of aluminium oxide. However, it reacts with steam to form aluminium oxide and hydrogen gas: 2Al + 3H2O (steam) → Al2O3 + 3H2. Sodium and potassium react vigorously with cold water, while calcium also reacts with cold water, though less vigorously.

Stainless steel is an alloy. It is composed of iron, chromium, nickel, and other elements. The alloy's corrosion resistance, strength, and versatility make it widely used in various industries. Unlike compounds or elements, stainless steel is a combination of multiple metallic elements.

Solder is an alloy primarily made of lead (Pb) and tin (Sn). It's widely used in electronics and plumbing to join metal parts together. The lead-tin combination melts at a relatively low temperature, making it ideal for creating strong, conductive, and durable joints in various applications.

The metal that will melt if you keep it on your palm is Ga, or gallium. Gallium has a melting point of approximately 29.76°C (85.57°F), which is just above room temperature.

Copper cannot be cut with a knife as it is a transition metal having strong metallic bonds, making it hard. Sodium, Lithium, and Potassium are alkali metals, which are soft because they have low density and weak metallic bonding, making them very malleable. Copper has tightly packed atoms, forming a solid structure that resists cutting.

Oxides come in four types: Amphoteric: React with both acids and bases (e.g., lead oxide, zinc oxide). Acidic: Form acids in water (e.g., sulfur trioxide). Basic: Form bases in water (e.g., calcium oxide). Neutral: Neither acidic nor basic (e.g., carbon monoxide).

Quicksilver is another name for Mercury. Mercury, in its liquid state, has a silvery appearance and flows easily, resembling the quicksilver used in historical terminology. Mercury is a chemical element with the symbol Hg and is the only metal that remains in liquid form at room temperature.