Water

UNIT 13

WATER

Learning Objectives

After the completion of this lesson, students will be able to:

* understand the importance, properties and uses of water.

* write the chemical equations for the reaction of water.

* explain water treatment methods.

* discuss about different methods of softening water.

* know about the causes and consequences of water pollution.

* list out the ways by which water pollution may be controlled.

Introduction

நீர்இன்று அமையாது உலெகனின் யார்யார்க்கும்

வான்இன்று அமையாது ஒழுக்கு – குறள்

Thirukkural says, without water there would be no life on the earth. Just like other living organisms, we also need water to survive. We need water for so many activities like cooking, washing, cleaning and irrigation. Water resources are getting depleted nowadays because of growing demand from increasing populations and lifestyle changes. There is also a reduction in the supply of water due to pollution of water sources and climate change which contributes to the rising variability in rainfall. We all depend on water for our living and so every individual is responsible for saving water. In this lesson, we will learn about the sources, properties and uses of water and also about water pollution and water treatment methods.