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Science (086) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] medium thorough-understanding
Which of the following statements about the physical properties of metals is INCORRECT? (A) Mercury is the only metal that exists as a liquid at room temperature. (B) Alkali metals such as sodium and potassium are hard solids with high melting points. (C) Silver and copper are the best conductors of heat and electricity among all metals. (D) Gold is highly ductile — one gram of it can be drawn into a very long, thin wire.
  1. A Mercury is a metal that exists as a liquid at room temperature.
  2. B Alkali metals such as sodium and potassium have high densities and high melting points.
  3. C Silver and copper are the best conductors of heat among metals.
  4. D Gold is the most ductile metal, and a wire of about 2 km can be drawn from one gram of it.
Generated by claude-sonnet-4-6 · 2026-06-26 01:05 · grounding rag
Model Answer

(B) is incorrect. Alkali metals such as sodium and potassium are soft (can be cut with a knife) and have low densities and low melting points — not high densities and high melting points.

Source: Chapter 3, Section 3.1 Physical Properties

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Explanation

The textbook explicitly states: "Alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife. They have low densities and low melting points." All other options are factually correct as per the chapter — mercury is the only liquid metal at room temperature; silver and copper are the best conductors of heat; and one gram of gold can be drawn into ~2 km of wire. In MCQs, find the one statement that directly contradicts the textbook.

Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.