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Matter in Our Surroundings — Question 6

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Question 6

Give two reasons to justify –

(a) water at room temperature is a liquid.

(b) an iron almirah is a solid at room temperature.

Answer

(a) Water at room temperature is a liquid because of the following reasons:

  1. At room temperature, water does not have a fixed shape and flows to fit the container's shape.
  2. A fixed volume is occupied by a fixed mass of water.

(b) An iron almirah is a solid at room temperature because of the following reasons:

  1. It has a definite shape and volume at room temperature.
  2. It is rigid.
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Science | Chapter 1: Matter in Our SurroundingsWeb Content — Quick Reference

Chapter 1: Matter in Our Surroundings — Quick Reference

states of matter particle nature change of state evaporation latent heat melting boiling sublimation

Quick Revision Points

  • Matter has mass and occupies space; made of particles with spaces, motion, and attraction
  • Three states: Solid (fixed shape/volume), Liquid (fixed volume, not shape), Gas (neither fixed)
  • Melting point of ice = 0°C (273 K); Boiling point of water = 100°C (373 K)
  • Latent heat of fusion of ice = 334 J/g; Latent heat of vaporisation of water = 2260 J/g
  • Sublimation: solid → gas directly (camphor, dry ice, naphthalene)
  • Evaporation: surface phenomenon at all temperatures; causes cooling; factors: surface area, temperature, humidity, wind
  • Temperature conversion: T(K) = T(°C) + 273
Exam Tips for Chapter 1
  • Read the detailed chapter notes for complete coverage of all NCERT topics.
  • Practice all NCERT in-text and back exercise questions — they are frequently asked in exams.
  • Focus on comparison tables, diagrams, and definitions — these are high-scoring areas.
  • For numericals (if applicable), practice at least 20 problems of varying difficulty.
  • Refer to the practice question bank (200+ questions) for thorough preparation.
Related Resources
  • Detailed Notes: ch01-matter-in-our-surroundings.html
  • Practice Questions: 100+ questions with answers in 05-practice-questions/
  • Chapter Test: 30-mark test paper in 06-tests/chapter-tests-30marks/
  • Formula Sheet: Complete formula reference in 03-teacher-aid/formula-sheet.html
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