abbreviations in natural resources lesson of class 9
Answers
Explanation:
This article brings you the CBSE Class 9 Science notes on chapter 14 ‘Natural Resources’ (Part-II) . In previous part, of this chapter, you learned about Natural Resourcesand its types. In this some other resources and various biogeochemical cycles in nature. These chapter notes are prepared by the subject experts and cover every important topic from the chapter. At the end of the notes you can try the questions asked from the discussed set of topics. These questions will help you to track your preparation level and get a hold on the subject.
Rain
Water and its Pollution
Soil. Formation and Erosion
Biogeochemical Cycles
Green House Effect
Ozonoe Layer and its Depletion
Key notes for Chapter - Natural Resources, are:
Rain
Rain is formed by evaporation and condensation of water through water cycle in.
Acid Rain
Acid rain is caused by the release of the gases like SO2 (sulphur dioxide) and NO2 (nitrogen dioxide) released from the emission of vehicles and combustion of fuels. These gases dissolve in rain water to form nitric acid and sulphuric acidacid
Water
Water is renewable resource.
It is essential for all physiological activities of plants and animals.
Water is mainly present in two forms:
(i) Surface water
(ii) Ground water.
Water Pollution
An undesirable change in the physical, biological or chemical properties of water (due to addition for foreign organic, inorganic substances) that adversely affects the aquatic life, and makes water less fit or unfit for use, is called water pollution.
The main causes of water pollution are as follows:
(i) Addition of harmful substances like fertilisers and pesticides to water
(ii) Removal of desirable substances like oxygen from water
(iii) Change in water temperature
Soil
It is the uppermost layer of Earth’s crust, which supports terrestrial plants, animals and microorganisms.
It is formed from the weathering of rocks by physical, chemical and biological activities by the action of wind, water and sun.
It is made up mainly of mineral particles, organic materials, air, water and living organisms