Chapter 1

Matter in our surroundings

Introduction

  • Everything in this universe is made of materials which scientist has names ‘matter’.
  • The matter is made up of very small tiny particles. It is not continuous but is particulate.
  • The matter is anything that occupies space and has mass.
  • Particles of matter have space between them and are continuously moving.
  • Particles of matter attract each other.

PHYSICAL NATURE OF MATTER

  1. Matter is made up of particles

If we take a 100 mL beaker, filling half of it with water and dissolve some salt/sugar. We will observe that there is no rise in water level and the salt/sugar has spread throughout the water (shown in the fig).

  1. How small are these particles of matter?
  • The particles of matter are very small – they are small beyond our imagination.

If we dissolve few crystals of potassium permanganate in about 1000mL of water, we will see the colour has changed. It shows that there must be millions of tiny particles in just one crystal of potassium permanganate, which keep on dividing themselves into smaller and smaller particles.