In-text Questions — Physical Properties — Metals and Non-metals

1. 12 marksNCERT Cl-10 Science, In-text Qs after §3.1, Q1

   Give an example of a metal which (i) is a liquid at room temperature. (ii) can be easily cut with a knife. (iii) is the best conductor of heat. (iv) is a poor conductor of heat.

   Hint. One metal covers the 'liquid' case all by itself — the other three need three different metals.

   Step 1 — (i) Liquid at room temperature. Mercury (Hg) — the only metal that is liquid at ordinary room temperature.

   Step 2 — (ii) Cut easily with a knife. Sodium (Na) or potassium (K) — alkali metals are so soft that a knife slices through them easily.

   Step 3 — (iii) Best conductor of heat. Silver (Ag) — silver conducts heat better than any other metal.

   Step 4 — (iv) Poor conductor of heat. Lead (Pb) — one of the noticeably poorer heat conductors among common metals.

   ✦ Answer: (i) Mercury (ii) Sodium or potassium (iii) Silver (iv) Lead.

   Where students slip. Naming mercury again for part (iv) — mercury already answers part (i); the question wants four different illustrative examples across the four properties.

2. 22 marksNCERT Cl-10 Science, In-text Qs after §3.1, Q2

   Explain the meanings of malleable and ductile.

   Hint. One word is about sheets, the other is about wires.

   Step 1 — Malleable. A malleable substance can be hammered or beaten into thin sheets without breaking — most metals show this property, which is why metals can be rolled into foils.

   Step 2 — Ductile. A ductile substance can be drawn out into thin wires without breaking — copper and aluminium wires used in electrical cables are everyday examples.

   ✦ Answer: Malleable = can be hammered into thin sheets without breaking. Ductile = can be drawn into thin wires without breaking.

   Where students slip. Treating the two words as synonyms — malleability is about withstanding hammering into sheets, ductility is specifically about being drawn into wires; a substance can in principle have one property without the other.

Solutions written by the tuition.in editorial team and checked against the NCERT Class 10 Science textbook, Reprint 2026-27 (jesc103.pdf) — five in-text question sets (15 questions total, not 18 as some older manifests claim) plus one end-of-chapter Exercise (16 questions, correctly counted). Unchanged by rationalisation.. Questions are referenced from the NCERT textbook for identification.