Nature’s Treasures Chapter Notes | Science Class 6 PDF Download

Introduction

Natural treasures refer to the elements and resources provided by nature that are essential for the survival of all living beings and enhance the quality of life. These treasures include air, water, sunlight, soil, plants, animals, and minerals. Each of these resources plays a crucial role in maintaining ecological balance and supporting life on Earth.
For example, we have fresh air to breathe, water to drink, and sunlight that helps plants grow. Trees give us fruits, wood, and shelter for animals and birds. The soil helps plants grow, which provides us with food. These treasures are very important for all living things on Earth, and without them, life would not be possible. We should take care of nature so we can continue to enjoy all these amazing gifts.

Air

What happens if we hold our breath for too long?

If we hold our breath for too long, our body doesn’t get enough oxygen, making it hard to function.

• The air we breathe has oxygen in it. 
• Our body needs oxygen to work properly. 
• If we hold our breath for too long, our body doesn’t get enough oxygen, making it hard to function. This is why we need oxygen to stay alive. 
• In the same way, most living things also need oxygen to survive.

 Importance of Oxygen for Survival 

• We can live without food or water for several days, but we cannot survive without oxygen for even a few minutes.

Composition of Air

Air is a mixture of gases, primarily composed of:

• Nitrogen (78%): The most abundant gas in the atmosphere, nitrogen is relatively inert and does not support combustion.
• Oxygen (21%): Essential for respiration and combustion processes.
• Other Gases (1%): Includes argon, carbon dioxide, neon, helium, methane, and trace gases.

Percentage means the number of parts out of 100. It is shown using the symbol '%'.

Characteristics of Air

Air is invisible, but its presence can be observed through its effects. For example:

• Wind: Moving air, which can vary from gentle breezes to strong storms.
• Physical Effects: Rustling leaves, fluttering pages of a book, or swaying clothes on a clothesline.

Leading Windmill Farms in India 

Some of the top windmill farms in India include the Muppandal Wind Farm in  Tamil Nadu, the Jaisalmer Wind Park in  Rajasthan, and the Brahmanvel Wind Farm in  Maharashtra.

Water

Why can't we use water from oceans and seas for drinking and agriculture?

Water from oceans and seas is salty (saline) and not suitable for drinking, agriculture, or industrial use.

Uses of Water in Daily Life 

• Drinking: Water is essential for staying hydrated and maintaining good health.
• Cooking: Water is used for preparing various meals and beverages.
• Bathing: Water is necessary for personal hygiene and cleanliness.
• Washing: Water is used for cleaning clothes, utensils, and other household items.
• Cleansing: Water is involved in cleaning various surfaces and items around the house.
• Agriculture: Water is crucial for growing crops and supporting agricultural activities.
• Industrial Purposes: Water is used in various industrial processes and manufacturing.

Sources of Water

• Rivers: Flowing bodies of freshwater that are vital for drinking, irrigation, and industrial use.
• Lakes: Large inland bodies of freshwater that provide water for various purposes.
• Ponds: Smaller bodies of freshwater used for irrigation and other local needs.
• Wells: Deep holes dug into the ground to access underground freshwater.

Water on Earth 

• Water covers about  two-thirds  of the Earth's surface, but most of it is found in  oceans and seas, which contain  saline  (salty) water. This saline water is not suitable for domestic, agricultural, or industrial use.
• For these activities, we need  freshwater, which is available in the form of ice sheets, snow, rivers, lakes, and underground sources. However, freshwater present in ice sheets and snow, as well as underground water, is often difficult to access. Only a small fraction of freshwater in ponds, rivers, lakes, and wells is easily accessible.

Understanding Water Pollution and Conservation

• Water pollution occurs when we throw trash and waste materials into freshwater sources  like rivers, lakes, and ponds. Waste from homes and industries also pollutes these water sources  when it is dumped into them. Let's explore other human activities that contribute to water pollution and discuss ways to reduce it.
• Polluted water  is not safe for living beings to drink. Since freshwater sources are limited, many parts of India face a water shortage . In some places, people have to walk long distances to fetch drinking water. Not everyone has the same access to water, which makes it important to conserve water  and use it wisely. We must also keep water clean and prevent pollution so that it remains safe for everyone to drink.
•  Here are some ways you can help conserve water:
  • Turn off the tap while brushing your teeth or washing your hands. 
  • Take shorter showers to save water. 
  • Fix leaks in taps and pipes to prevent water wastage. 
  • Use a bucket instead of a hose to wash your car or water your garden. 
  • Collect rainwater in barrels for gardening and other uses. 
  • Be mindful of how much water you use when cooking and cleaning. 

Rainwater Harvesting

• Water harvesting involves collecting and storing rainwater for future use.
• This practice is common in many buildings, homes, and schools.
• Traditional methods of water harvesting, like stepwells (Bawadi in Rajasthan and Vav in Gujarat), are used in some regions to collect rainwater and water seeping from nearby lakes, ponds, and rivers.
• Stepwells have stone-lined trenches that allow water to seep in.

World Water Day is observed on 22nd March every year.

Energy from the Sun

What are some ways we can use the Sun's energy directly?

We can use the Sun's energy directly for cooking in a solar cooker and for heating water in a solar water heater.

The importance of sunlight as the main source of energy:

• Sunlight helps plants make their food. The Sun also gives warmth and light to all living things on Earth. It is the main source of energy for everyone.

Forests

Importance of Forests for Wildlife

• Forests serve as a natural home for many wild animals, birds, and insects, providing them with food and shelter.
• The diversity of life forms in forests ensures that every living being has enough food. For example, plants provide fruits, seeds, and leaves, while other animals may provide carrion or prey.
• Forests are crucial for maintaining the balance of nature, as every animal depends on other life forms for survival.

Threats to Forest Cover 

• Over the years, forest cover has been decreasing, primarily due to  human activities like large-scale cutting of trees  for agriculture, urbanization, and logging.
• It takes many years to grow a new forest or restore lost forests. Therefore, it is essential to  preserve and use forests responsibly  to give them enough time to regenerate.

Van Mahotsav: A Festival for Forests 

• Van Mahotsav is a week-long event celebrated across the country in July  to promote forest conservation.
• During this festival, new plants and trees are  planted, and awareness about respecting forests is raised.
• The aim is to increase the  green cover  and encourage communities to take part in forest conservation efforts.
• Everyone can plan a Van Mahotsav in their community to help  increase green cover  and raise awareness about the importance of forests.

Respecting and Protecting Forests in India 

• Since ancient times, India has had a strong tradition of  respecting, protecting, and preserving forests  . 
• One example of this is the  sacred groves, which you learned about in the chapter 'Diversity in the Living World.' 
• Many common people have made  efforts to stop tree cutting  and save forests. 

The Chipko Movement 

• One famous effort is the  Chipko movement, which began in the early  1970s in Uttarakhand  (formerly part of Uttar Pradesh). 
• Local  women  played a big role in this movement by  hugging and encircling trees  to protect them from being cut down. 

Soil, Rocks, and Minerals

Soil

• Soil is made up of various components such assand, insects, and worms. There are also many tiny organisms in the soil that we can't see without a microscope.
• When plants and animals die, they break down and become part of the soil, adding to its composition.
• Soil samples taken from different locations can vary in color because they contain different materials. 
• Soil is a precious resource that supports a wide range of plants and animals, making it crucial for biodiversity. It is formed over thousands of years through the gradual breakdown of rocks by natural forces like the sun, water, and living organisms.
• Soil is created by the breaking apart of rocks over a long time, a process caused by the Sun, water, and living organisms.
• Different types of soil are suited for various purposes. Some soils are excellent for growing specific plants, while others are better for making bricks used in building construction.
• Forests are home to a variety of soils, each supporting different types of plants and animals.
• Soil is not just dirt; it is a vital part of the ecosystem that supports a wide range of life forms, contributing to the planet's overall biodiversity.

Rocks

Rocks and Their Uses

Rocks are an essential part of our environment and have various uses:

• Rocks are used in construction for houses, buildings, roads, dams, and other structures. For example, slate is used for roofing, and laterite can be used for making bricks.
• Rocks like granite, sandstone, and marble are important in construction and other applications.
• Rocks have been used by humans for thousands of years to make tools such as hand axes and arrowheads.

What Are Rocks Made Of?

• Rocks are made up of minerals, which are the building blocks of rocks. Important metals like aluminium, gold, copper, and iron are extracted from minerals. These metals are used in various products, including airplanes, cars, jewellery, cosmetics, and electrical equipment. For instance, mobile phones contain several minerals like gold, silver, and copper.
• Rocks are vital to our lives, and their formation takes thousands to millions of years. Therefore, it is crucial to conserve rocks and use them responsibly. Rocks and minerals are transported using vehicles, most of which run on fossil fuels .

Fossil Fuels

• Fossil fuels are formed from the remains of tiny organisms and plants that were buried deep in the Earth. 
• Over millions of years, these remains are transformed into petroleum, natural gas, and coal. 
• Petroleum, natural gas, and coal are often grouped together as fossil fuels.

Common Types of Fuels

• Petrol and diesel are the most commonly used fuels for vehicles. 
• These fuels, along with kerosene, are derived from petroleum.
• Natural gas is used for cooking and generating electricity. Recently, it has also been used in the form of  Compressed Natural Gas (CNG)  as a cleaner fuel for vehicles, producing less pollution than petrol or diesel. 
• Coal  is primarily used for generating electricity and is found in various parts of India.  

Transition in Cooking Fuels: From Traditional to Modern

• Traditional Cooking Fuels:  In the past, people used things like coal, wood, and dung cakes as fuels for cooking. These materials were common but not very clean for the environment.
• Modern Cooking Fuels:  Nowadays, many households have switched to using natural gas and Liquefied Petroleum Gas (LPG). These fuels are less polluting and more efficient, making them a better choice for the environment and for cooking.

 The Need for Alternate Energy Sources 

•  As  fossil fuels  are limited in supply, continuing to use them at the current rate will deplete these resources quickly. 
• To avoid running out, it is important to explore  alternative energy sources . 
• Additionally, the burning of fossil fuels releases smoke and carbon dioxide, which contributes to  air pollution. 
• The heavy reliance on fossil fuels for  transportation  and domestic use has led to significant air quality issues.

Natural Resources: Renewable and Non-renewable

How do we use natural resources to make our lives easier?

We use natural resources to create useful things like electric bulbs, furniture, solar panels, and bicycles, which make our lives easier and more comfortable.

The importance of natural resources and human-made resources:

• Natural resources are the gifts of nature that fulfill our needs and are essential for sustaining all life forms on Earth.
• For instance, we obtain  heat and light from the Sun,  water from rivers, and  food from plants and animals. These resources are vital for our survival and well-being.
• Natural resources are not only crucial for our survival but are also used to create many useful things that make our lives easier and more comfortable. For example, we use natural resources to make  electric bulbs, furniture, solar panels, bicycles, and many other items that enhance our daily lives.
• In contrast, resources created by human beings using natural resources are called  human-made resources. These include products and tools that we manufacture to improve our quality of life.

Types of Natural Resources 

Natural resources can be classified into  renewable  and  non-renewable resources  based on their replenishment rate.

• Renewable Resources:  These resources are replenished by nature within a reasonable period of time. Examples include air, water, and  forests. These resources can be renewed and restored by natural processes, and we should use them judiciously to ensure their availability for future generations.
• Non-Renewable Resources: These resources take millions of years to form and are found in limited quantities. Once used, they cannot be replenished within a human timescale. Examples of non-renewable resources include  minerals, soil, rocks, coal, petroleum  , and  natural gas. These resources are exhausted once used, and their limited availability makes it crucial to use them wisely.

Resources We Use

Natural resources like air, water, soil, plants, and animals are essential for our daily lives. We use them for things like drinking, cooking, washing, and growing food. Natural resources are integral to daily activities.
Examples include:

Key Points

• Natural treasures are resources provided by nature, such as air, water, sunlight, soil, forests, and minerals.
• Air is essential for respiration and life, composed of nitrogen, oxygen, and other gases.
• Water is vital for life and has multiple uses; it must be conserved and protected from pollution.
• The Sun provides energy for various life processes and human activities.
• Forests are important for biodiversity, soil conservation, and climate regulation.
• Soil is formed from weathered rocks and supports plant life.
• Rocks and minerals are used in construction and manufacturing.
• Fossil fuels are energy sources formed from ancient organisms; they have significant environmental impacts.
• Renewable resources can be replenished naturally, while non-renewable resources are finite.
• Conservation of natural resources is essential for sustainability and future generations.