States of Water - Class 6 Science - New St. Mery English School 

Water is one of the most essential substances on Earth. It exists all around us in different forms — as ice, liquid water, and water vapour. These are known as the three states of water. The ability of water to change from one state to another makes it a unique and vital resource for all living beings. In this chapter, we will learn how water changes its form through melting, freezing, evaporation, condensation, and sublimation, and how these processes are connected to our daily life and the water cycle. Understanding the states of water helps us appreciate the natural balance of our environment and the importance of conserving water.

States of Water - Class 6 Science - New St. Mery English School

About three-fourths of the earth's surface is covered with water. Most of the water on the earth exists in the liquid form in river, lakes, seas and oceans.

The process of conversion of a solid into its liquid state occurs at a fixed temperature is called melting point.

Melting point of water at °C = 0 °C                                          Melting point of water at °F = 32 °F

The process of conversion of a liquid into its solid state is called freezing. Freezing of a liquid into its solid state occurs at a fixed temperature is called the freezing point

Freezing point of water at °C = 0 °C                                      Freezing point of water at °F = 32 °F

Vaporisation

The process of conversion of a liquid into its gaseous state is called vaporisation.                                                                              

There are two ways to perform vaporisation.

1- By evaporation

2- By boiling

Difference between Evaporation and Boiling

Evaporation is a slow conversion of water into its vapour state but Boiling is a fast conversion of water into its vapour state.

                                        Condensation

The process of conversion of a gas or vapour into its liquid states is called condensation. Condensation takes place at a particular temperature called condensation point.

Cloud formation

When  the temperature of air increases, it expands this  makes the air lighter and causes it to rise. In the atmosphere, taking water vapoure with it . Water vapoure is formed when water bodies evaporates due to the heat of the sun . As the air rises, it begins to cool. The  water vapoure  condenses on dust particles present in the atmosphere to from millions of tiny droplets Tiny ice crystals could also from if it is very cold. This cluster of tiny water droplets floating in air and appear as clouds.

Water cycle

The continuous circulation of water from the earth's surface to the air and from the air back to the earth's surface is called the water cycle.

How does water cycle happen

Water in seas, lacks, ponds, or streams evaporates due to the heat of the sun. this water vapoure rises. The air higher up in the atmosphere is cooler which cools the water vapoure  and causes it to condenses into tiny drops of water. Many such tiny drops  of water come together to form clouds. As the clouds get cool further, the water drops become bigger. When they become too heavy, they fall on the earth as rain. Rainwater falls on seas, river, lacks, ponds and streams. The water evaporates again and  this goes on repeating. Thus the water cycle in nature continues.

Rain

Rain is a types of precipitation falling from the atmosphere to the  earth. Raindrops or ice crystals from in clouds and fall to the ground when  they become heavy enough that the air can no longer    support them up.

Lighting and thunder

A loud sound or crashing noise after a flash of  lighting is called thunder. Thunder and lighting occur during they result from a heavy flow of electric charges either between two clouds or between a cloud and a tall object such as tree or building.

Why do lighting and thunder occur?

A scientist named Benjamin franklin find this out.  He flew a silk kite into the clouds during a thunderstorm, typing a metal key to thread of the kite. he got an electric shock when he touched the key. You  have read that an electric current can give an electric shock . Therefore, he concluded that electricity got generated in the clouds during thunderstorm and flows down the wet kite thread to the metal key. That is why the key gave an electric shock when touched.

Flood and their effects

Most of the rainfall in our country occurs in the monsoon season. the amount of rainfall varies from one place to place. When ,it rains heavily, it may cause the water level of lakes, ponds and rivers to rise, this is called floods.

Effects of flood

1- Flood causes great damage to crops, animals and humans.

2- Flood water can damage structures such as building.

3- Flood can lead to landslides.

4- People and animals may drown in flood waters and die.

5- Flood can cause a shortage of flood crops as  entire harvests may be destroyed.

6- Unhygienic conditions caused by floods can lead to spread waterborne diseases like cholera and typhoid.

7- Scarcity of drinking water  may occur as the water gets contaminated.

Drought and their effect

If rain does not fall on a region for a long time, it can lead to a condition called a drought. A drought is an extended period of months or years when a region does not receive any rainfall. A drought can cause a lot of damage and harm to life.

The effects of drought 

1- Crop. yield becomes less and the soil dries up as it continues to lose water  by evaporation.

2- Lack of water may cause the death of livestock.

3- Water shortage may cause death of people living in drought affected areas.

4- Food and fodder become scarce. it may lead to malnutrition.

5- Dehydration and other related diseases are common during drought.

6- People of drought-affected areas may migrate due to lack of alternative food sources. The migration can put civic and economic pressure on non- drought areas.