Curiosity Class 8 Science Chapter 7 Particulate Nature of Matter Case Study Questions

Download CBSE and ICSE Books in PDF Format

Reading Time: 6 minutes

Last Updated on December 17, 2025 by XAM CONTENT

Hello students, we are providing case study questions for class Class 8 Science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class Class 8 Science. In this article, you will find case study questions for cbse class Class 8 Science chapter 7 Particulate Nature of Matter.

Chapter	Particulate Nature of Matter
Type of Questions	Case Study Questions
Nature of Questions	Competency Based Questions
Board	CBSE
Class	Class 8
Subject	Science
Useful for	Class 8 Studying Students
Answers provided	Yes
Difficulty level	Mentioned
Important Link	Class 8 Science Chapterwise Case Study

Table of Contents

Customised Study Materials for Teachers, Schools and Coaching Institute

Case Study Questions on Particulate Nature of Matter

Case Study 1: The Principle of Interparticle Space (Based on Activity 7.7)

A student conducts Activity 7.7 (Refer NCERT) to investigate interparticle spaces in liquids. A glass vessel is filled halfway with water (Level A). Two teaspoons of granulated sugar are carefully added, causing the level to momentarily rise to B. After thorough stirring, the sugar dissolves completely, and the final level is marked C. The student notes that the volume represented by Level C is less than the theoretical sum of the separate volumes of the water and the added sugar. The experiment is then repeated using two teaspoons of fine sand instead of sugar. The sand settles at the bottom, and the final water level is observed to be noticeably higher than the initial Level A, showing no sign of dissolution.

Questions

Q1. What is the main reason that the final volume of the water-sugar solution (Level C) is less than the expected volume (Level B)?
A. The sugar undergoes a chemical change, reducing its mass.
B. Water molecules react with sugar particles, changing their state.
C. The constituent particles of sugar occupy the interparticle spaces of water.
D. Water evaporates rapidly due to stirring, reducing the overall volume.

Q2. Justify the statement: “Dissolving sugar in water is a demonstration that matter is particulate in nature.”

Q3. If V_water is the volume of water and V_sand is the volume occupied by the sand grains, express the approximate relationship between the final volume (V_final) of the water-sand mixture and V_water and V_sand.

Q4. Why does sand, a solid, fail to demonstrate the phenomenon observed with sugar, another solid, when mixed with water?.

Answers

A1. C. The constituent particles of sugar occupy the interparticle spaces of water.
Reasoning: When sugar dissolves, it breaks up into its constituent particles. These tiny particles separate and distribute themselves by occupying the available spaces between the water particles, known as interparticle spaces. This mixing at the microscopic level means the final volume is not a simple sum of the initial volumes.

A2. Explanation: The successful dissolution of sugar into water, where the sugar particles seem to vanish yet their presence is confirmed by taste, supports the idea that matter is composed of extremely small particles. Crucially, the observation that the particles of sugar separate and fill the volume between the water particles demonstrates that water particles must have spaces between them (interparticle spaces), a key characteristic of the particulate nature of matter.

A3. Explanation: V_final≈V_water+V_sand.
Sand is an insoluble solid in water. Since sand does not dissolve, its constituent particles cannot break up and occupy the voids between the water particles. Instead, the sand particles settle down and occupy physical space in the container, meaning the final volume of the mixture is approximately the sum of the volumes of the two components.

4. Explanation: The ability of sugar to dissolve (and hence spread into the interparticle space) depends on the forces holding its particles together. In the case of sugar, the water particles are able to pull out the constituent particles, allowing dissolution. However, in the case of sand, the constituent particles are held together so strongly that the water particles are unable to pull them out, classifying sand as insoluble in water.

We hope the given case study questions for Particulate Nature of Matter Class Class 8 helps you in your learning.