Introduction

Everything in our surroundings— stones, clouds, stars, animals, and even a small drop of water is matter. Matter is anything that occupies space and volume. In other words, they have mass and volume.

Early Indian philosophers classified in the form of five basic elements called panch tatva— air, water, fire, earth and sky. According to them, everything was made up of these five basic elements. Modern day scientists classify matter based on physical and chemical properties.

• Chemical properties: compound, elements, mixtures

• Physical properties: solid, liquid, gases

Physical properties

• Matter is made up of molecules

• Particles of matter have space between them

• Particles of matter are continuously moving- this is because of kinetic energy. Kinetic energy increases with temperature. Diffusion is the intermixing of 2 different kinds of matter.

• Particles of matter are attracted to each other. Attraction between particles of matter is greater in solid, moderate in liquid and very less in gases. This is why is is much easier to put your hand through liquid/gas but is harder to put your hand through a solid. Cohesion is the force of attraction between particles of the same substances. The force of attraction between constituent particles of any form of matter is called intermolecular/interparticular attraction.