Properties of Water for Class 3 Science

Water is essential part of all living things. So, it is important to know about different properties of water such as colour, taste, fluidity, etc. In this concept, the students will know more about how the states of water change at different temperatures.

After reading the concept, students will be able to:

• Differentiate between freezing point and melting point.
• Answer what is boiling point of water.
• Explain about condensation of water vapour.
• Recall any 6 properties of water.

Each concept is explained to class 3 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Properties of Water provided in PDF format.

• Water is an essential component for any living being to survive on Earth.
• Around 70% of our Earth is covered by water. So, being the only planet with water, the Earth is also called the ‘Blue planet’.
• Water is present everywhere on Earth in different forms.

 

States of Water:

• The biosphere on Earth shows the presence of water in all three states, i.e. solid, liquid and gas.
• When the temperature reaches 0ºC, liquid water solidifies to form ice. It is called the freezing point of water.
• When the temperature starts rising above 0ºC, ice starts converting into liquid water by melting. It is called the melting point of water.
• At 100ºC, the liquid water converts into water vapour by evaporation. It is called the boiling point.
• The evaporated water can be cooled down to get liquid water by condensation.

 

Conversion of Water in Different States:

• Freezing: The conversion of water from liquid to solid state (ice) at 0ºC is called solidification or freezing of water.
• Melting: The conversion of water from a solid state (ice) to a liquid form above 0ºC is called the melting of water.
• Evaporation: The conversion of water from liquid to gaseous state (water vapour) at 100ºC is called evaporation of water.
• Condensation: The conversion of the gaseous state of water (water vapour) into liquid is called condensation.

 

Different Properties of Water:

1. Colour
• We see a river or pond where the colour water is greenish or brownish. The water in the ocean and seas looks bluish. Such colour appears due to aquatic plants, soil debris, different impurities, minerals, etc.

• But the water in its pure form does not have any colour as it does not have any impurities.
1. Taste
• Pure water is tasteless.
• The water we use in the house may contain some added minerals that give a mild taste to it.
• The purest water is called distilled water.
2. Odour
• Pure water is odourless.
• Drainage water looks black and gives off a foul smell because it is mixed with sewage.
• Water in juices or any cold beverage gets the colour/taste/smell of other food ingredients present in it.
3. Shape and Size

• Though water exists in all three forms, most water on Earth is in the liquid form.
• In the solid state, water has a definite shape.
• In the liquid state, it does not have a specific shape and takes the shape of its container.
• As water vapour, it does not have a specific shape and floats freely like other gases.

5.Fluidity

1. • Water in a liquid state can flow from one place to another.
   • Fluidity is the ability of a substance to flow.
   • Due to its fluidity, it is easily transported to various areas within the cities via pipes.

6.Water as a Heat Insulator

 

• Ice acts as an excellent heat insulator. The Eskimos use this property to build their houses called igloos.
• Igloos are made with blocks of ice. These keep the inside of the house warmer than the cold surroundings.

 

7.Cooling Effect Due to Evaporation of Water

1. • Water, when it evaporates from a surface, absorbs the heat of that surface and cools it down to produce a cooling effect.
   • This is the reason why people sprinkle water on hot terraces in summer.
   • Also, our body cools down after we sweat in summer due to the cooling effect of water caused by evaporation.

 

8.Excellent Solvent

• A solvent is mainly a liquid in which other materials dissolve.
• Water is used as a solvent on a large scale due to its excellent capacity for dissolving many solutes.
• So, water is called the ‘universal solvent’.
• The combination of solute and solvent is called a solution. The solute is generally present in small quantities, whereas the solvent is in larger quantities.

Examples:

•  Solution of salt in water, solution of sugar in water.

 

New Words:

 

Misconception:

Water Is Called a ‘Universal Solvent’ but Cannot Dissolve All Substances

It happens because the water molecules can join with many other molecules. Still, molecules of substances like oils do not bind very well with water molecules and do not dissolve in water.