CBSE Notes for Class 9 Chapter 14 Natural Resources
Chapter 14 Natural Resources CBSE Notes for Class 9: Our Earth Planet is the only place where life exists. Various factors like water, ambient temperature, air, minerals, food, and sunlight contribute to the life forms on Earth. These resources are essential for life to exist on Earth. In this article, every aspect of ‘Natural Resources’ is discussed in detail. You can check the notes for chapter 14 of the Science subject below.
Resources on the Earth
A type of zone where the three atmospheres, the lithosphere, and the hydrosphere interact and create life forms is known as the Biosphere. The surface of the earth contains 75% water and this is known as the Hydrosphere. Earth has an outer crust which is known as the Lithosphere. Also, the earth is covered by air which is called the Atmosphere. Because of the atmosphere, the lithosphere, and the hydrosphere, life is possibly happening on our planet earth. Additionally, the earth consists of both biotic (living things) and abiotic (air, soil, and water) components.
Air
The air is composed of a mixture of gases such as oxygen, carbon dioxide, nitrogen, and water vapor. To make a successful life on the earth, oxygen is required for the organisms to get energy. Other planets like Mars and Venus have 95% to 97% of carbon dioxide in the atmosphere. Also, living organisms make changes in the atmosphere whether it is going to be a strong or gentle breeze or a heavy storm. The air of the atmosphere contains 21% oxygen, 1% other gases, and 78% nitrogen. The temperature of the earth is steady because of the atmosphere. When the temperature of the earth increases quickly, the atmosphere prevents it during the daytime.
Air Pollution
Nowadays, we know that the quality of air is decreased due to the activities of living organisms. Oxides such as nitrogen and sulfur are increasing continues due to the burning of fossil fuels. And, it is very dangerous to inhale these gases. These gaseous also form acid rain when dissolved in the rain. The introduction of various pollutants and other harmful materials into the air results in air pollution.
Causes of air pollution
Air pollution causes due to emitted gases from vehicles, combustion of fuel, emitted gases during agricultural activities, mining activities, domestic sources, and released components of factories and industries, etc.
Effects of Air Pollution
The harmful effects of air pollution include acid rain, global warming, ozone layer depletion, disease, and the extinction of animals.
Water
A large area of the earth’s surface is occupied by water. The atmosphere of the earth contains a small amount of water vapor. Water found in lakes, rivers, and ponds is the source of fresh water. Our two-third body is also made up of water. We all need water to keep our body temperature normal. Other than this, water is required for domestic purposes, industrial purposes, and agricultural purposes. On the earth, the surface contains 3% of fresh water.
Water Pollution
Water includes pesticides, fertilizers, and some other substances dissolved in it. Both rivers and lakes contain dumped waste from towns, industries, and factories. Unwanted substances mercury salts and other substances that are added to water bodies make water polluted. Water pollution is caused by contamination of water bodies, Agriculture, Urbanisation, Religious and Social Practices, Industries, Withdrawal of water, etc.
Soil
Soil is the formation of rocks which is broken down by chemical, physical and biological processes. The uppermost layer of the Earth’s crust which forms by the continuous weathering of mountains is called Soil. There are different factors that contribute to the making of soil. Clay, silt, sand, and loam are types of soil. The sun is one of them which heats and breaks up rocks into smaller pieces. This forms cracks in the rock and makes the fine particles of soil. In addition, water bears hard rock for a long period of time and due to abrasion, it converts into small particles. The living organisms also influence soil formation. The growth of plants like moss breaks up the rocks.
Humus
Humus is an important component of soil because it increases the fertility of the soil. The formation of soil takes place after the decomposition of twigs, the remains of animals, the remains of plants, and dried leaves.
Soil Pollution
When the soil becomes less reproductive due to dangerous or toxic chemicals, it is said to be soil pollution. The causes of soil pollution include industrial wastes, accidental oil spills, fertilizers, acid rain, insecticides, etc.
Biogeochemical Cycles
In order to make a stable system, the interaction between abiotic and biotic components of the biosphere is needed. Both biological chemical and geological process makes the Biogeochemical cycle.
Nitrogen Cycle
Some vitamins, proteins, and nucleic acids like DNA and RNA include nitrogen as essential molecules. The demands of various environmental activities are fulfilled by the recycling and reusing processes of nitrogen. In short, the recycling and reusing of nitrogen in various forms are known as the Nitrogen cycle.
Water cycle
The water cycle is a process where evaporation takes place and through the rain, it again falls on the land but after falling water flows back into the sea via rivers. During this process, all the animals and plants use the water and it takes time to return to the water.
Carbon cycle
Molecules such as carbohydrates, fats, vitamins, and proteins are present in the living forms and they contain carbon in them. When carbon is circulated and converted between living forms and the environment, it is referred to as the Carbon cycle.
Greenhouse effect
If the solar radiation is trapped by greenhouse gases in Earth’s atmosphere then that phenomenon is referred to as the Greenhouse effect. Greenhouse gases are methane, carbon dioxide, Nitrous oxide, chlorofluorocarbons, and water vapor.
Oxygen cycle
Oxygen is the most essential component on the earth for all living things. A biological process that maintains the oxygen level in the atmosphere is called as Oxygen cycle.
Ozone Layer
When the upper reaches of the atmosphere contain O3 then it is known as Ozone. It is poisonous but useful in absorbing dangerous radiation from the sun.
Frequently Asked Questions on CBSE Notes Natural Resources
Which greenhouse gas is responsible for leading global warming?
Carbon dioxide is also a greenhouse gas and when this gas will present in the atmosphere in more content then this can lead to global warming.
What is another term for the water cycle?
The hydrologic cycle is another term that refers to the water cycle. The hydrologic cycle involves precipitation, evaporation, and condensation as a major process.
What do CFCs and HCFs stand for?
CFCs refer to Chlorofluorocarbons, while HCFs refer to Hydrochlorofluorocarbons.
What is the function of humus?
The roots of plants need both oxygen and water. And, water and oxygen are provided to the plant roots by humus.
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