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Which is the most malleable metal?
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Answer: Option D — Gold
Detailed Solution
Malleability is the property of a material that allows it to be beaten or hammered into thin sheets without breaking. It is one of the typical physical properties of metals. Gold is the most malleable of all metals.
Gold is so malleable that one gram of gold can be beaten into a sheet of about one square metre. Gold leaf can be made so thin, about 0.1 micrometre (0.0001 millimetre), that light passes through it, giving it a greenish-blue colour. Gold leaf is used for decorating temples, statues, picture frames, books and even sweets. Silver is the next most malleable metal; thin silver foil called "varq" or "vark" is used to decorate Indian sweets.
Gold is also the most ductile metal. Ductility is the ability to be drawn into thin wires. One gram of gold can be drawn into a wire about 2 kilometres long.
Why metals are malleable and ductile: in metals, atoms are held together by metallic bonds, in which positive metal ions are surrounded by a "sea" of free-moving electrons. When a metal is hammered, layers of atoms can slide over each other without breaking the bonds, because the electrons continue to hold the ions together.
Other properties of gold:
It is a noble metal; it does not react with air, water or most acids, so it does not tarnish or rust. It dissolves only in aqua regia (a 3:1 mixture of concentrated hydrochloric and nitric acids) and in solutions of cyanide.
Its chemical symbol is Au, from the Latin word "aurum".
Pure gold is 24 carats; it is too soft for jewellery, so it is mixed with copper or silver to make 22-carat (91.6%) gold. In India, hallmarking of gold jewellery, certified by the Bureau of Indian Standards (BIS), became mandatory in 2021.
In India, gold is mined mainly at the Hutti Gold Mines in Karnataka. The Kolar Gold Fields, also in Karnataka, were closed in 2001.
Why not the other options?
- ✗Silver is the second most malleable metal and the best conductor of electricity.
- ✗Aluminium is malleable and used in foils, but less so than gold.
- ✗Copper is malleable and ductile and used in wires.
Quick tip
Remember: Gold = most malleable and most ductile metal (symbol Au, dissolves in aqua regia); silver = best conductor of electricity; mercury = liquid metal; Hutti = gold mine in Karnataka.
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Metals, Non-metals & Metallurgy — Preparation
This question tests your understanding of Metals, Non-metals & Metallurgy, a key topic in the General Knowledge section. The detailed solution above uses a step-by-step approach to show the reasoning, and where available, a shortcut that helps you solve similar questions in under 90 seconds during the actual exam.
This topic covers the properties of metals and non-metals, the reactivity series, ores and minerals of common metals, metallurgy (concentration, roasting, calcination and refining), alloys and their compositions, and the corrosion of metals. Common questions ask about the ore of a metal (bauxite for aluminium and haematite for iron), the composition of alloys (brass is copper and zinc, and bronze is copper and tin), the best conductor of electricity (silver), and the most abundant metal in the Earth's crust (aluminium). Galvanisation coats iron with zinc to prevent rusting. Practise the metals, non-metals and metallurgy questions below, written in the style of the general awareness sections of exams such as SSC, banking, railways, CUET GAT, MAH CET and CLAT. Each question comes with a detailed explanation that adds related facts, so every question helps you revise more than one point.