INTRODUCTION

INTRODUCTION

As we look at our surroundings, we see a large variety of things with different shapes, sizes and textures. Everything in this universe is made up of material that scientists have named “ matter ”. The air we breathe, the food we eat, stones, clouds, stars, plants and animals, even a small drop of water or a particle of sand – everything is matter. We can also see as we look around that all the things mentioned above occupy space and have mass. In other words, they have both mass* and volume**.

Since early times, human beings have been trying to understand their surroundings. Early Indian philosophers classified matter in the form of five basic elements – the " panch tatva "– air, earth, fire, sky and water. According to them everything, living or non-living, was made up of these five basic elements. Ancient Greek philosophers had arrived at a similar classification of matter.

Modern-day scientists have evolved two types of classification of matter based on their physical properties and chemical nature.

In this chapter, we shall learn about the matter based on its physical properties. Chemical aspects of matter will be taken up in subsequent chapters.

Note:

*   The SI unit of mass is kilogram (kg).

** The SI unit of volume is cubic metre (m³). The common unit of measuring volume is litre (L) such that 1L = 1 dm³, 1L = 1000 mL, 1 mL = 1 cm³.

Source: This topic is taken from NCERT TEXTBOOK