Elements, Metals, Materials & Chemicals MCQs with Answers

Elements, Metals, Materials & Chemicals — Master Reference for Pakistani Competitive Exams

The chapter Elements, Metals, Materials & Chemicals is one of the highest-scoring Everyday Science clusters in Pakistan’s PPSC, FPSC, NTS, CSS, PMS, OTS, CTS, BPSC, KPPSC and SPSC One Paper exams. Almost every Junior Clerk, Tehsildar, Assistant, Sub-Inspector, Lecturer and BPS-14 to BPS-17 paper carries 3–5 MCQs from this chapter — and it is core CSS Screening MPT (General Science & Ability) content. This page consolidates 60 solved MCQs covering conductors / insulators / semiconductors, the most-tested alloys (brass, bronze, nichrome, stainless steel, bell metal, amalgam), ores (bauxite, pitchblende, hematite), allotropes of carbon, common compounds (washing soda, bleaching powder, laughing gas, marsh gas), “only one of its kind” facts (only liquid metal = mercury, only liquid non-metal = bromine), synthetic materials (rayon, nylon, teflon, vulcanised rubber, pyrex), and the colours imparted to glass by metal oxides. For wider context, see Wikipedia: Alloy and the official IUPAC Periodic Table of Elements.

Most-Asked Alloys — Quick Reference

Famous “Anchor Facts” — Most Tested in Exams

• Best conductor of electricity — Silver (then copper, gold, aluminium).
• Lightest metal — Lithium (least dense).
• Only liquid metal at room temperature — Mercury (Hg).
• Only liquid non-metal at room temperature — Bromine (Br).
• Most malleable & ductile metal — Gold.
• Hardest natural substance — Diamond (allotrope of carbon).
• Bulb filament — Tungsten (W); bulb filling — Nitrogen (sometimes argon).
• Chief ore of aluminium — Bauxite. Source of radium — Pitchblende.
• Element common to all acids — Hydrogen. Common to all bases — Oxygen.
• Bleaching powder = chloride of lime (Ca(OCl)Cl).
• Marsh gas = methane (CH₄). Laughing gas = nitrous oxide (N₂O).
• Washing soda = sodium carbonate (Na₂CO₃) — removes water hardness.
• Heavy water contains deuterium (D₂O).
• Purest form of iron — wrought iron (≥99.5% pure).
• Steel has the least carbon among iron forms (0.1–2%).
• Galvanised iron = iron coated with zinc.
• Welding gases — oxygen + acetylene (oxy-acetylene welding).
• Transistors made from silicon & germanium.
• Photo films contain silver (silver halides).
• Non-stick pans coated with Teflon (PTFE).
• Vulcanisation of rubber uses sulphur at 140–160°C.
• Cement raw materials = limestone + clay + iron ore.
• Pyrex glass resists heat & chemicals (borosilicate).
• Glass colours: emerald green = Cr₂O₃; blue-violet = CoO; red = AuCl₃.
• 18-karat gold = 75% pure gold.
• Average sea-water salinity ≈ 3.5% (35 ppt).
• Coinage metals = Cu, Ag, Au.