The Water Cycle Chapter Notes | Science Class 2 ICSE PDF Download

Introduction

Changes in Water Forms

• Water changes its form through heating or cooling.
  • Evaporation: When water is heated, it turns into water vapour.
  • Condensation: When water vapour cools, it turns back into liquid water.
  • Freezing: When water is cooled, it turns into ice.
  • Melting: When ice is heated, it turns back into liquid water.
• Water vapour is another name for steam.

Water Cycle

•  The heat of the sun heats up the water of rivers, lakes, ponds and seas. 
• Some of this water changes into water vapour and rises up in the sky.
• These cool down to form clouds with tiny droplets of water.
• These droplets join to form big heavy drops.
• The clouds cannot hold them and they fall down in the form of rain.
• Rainwater flows into rivers, lakes, etc.
• In colder places, these water drops come down in the form of snow.
• The snow melts and turns into water and flows into streams and rivers.
• Thus, the water cycle in nature continues.
•  The water cycle is the journey of water from the earth to the sky and back to the earth.