Pathik — CBSE Class 6–12 Notes, Worksheets & MCQ Quizzes

 Class 9 – Chapter 3: Atmosphere and Climate https://link.amazon/B01vdn9oG 1. Atmosphere:-  The atmosphere is the blanket of air surrounding the Earth. Held by Earth's gravity. Essential for life because it: Provides oxygen. Protects Earth from harmful UV rays. Maintains Earth's temperature. Controls weather and climate. 2. Composition of Atmosphere:-  Gas Percentage Nitrogen 78% Oxygen 21% Argon 0.93% Carbon dioxide 0.04% Other gases 0.03% Other Components Water vapour (0.1–0.4%) Dust particles Importance Nitrogen helps plant growth. Oxygen supports life. Carbon dioxide is used in photosynthesis. Water vapour forms clouds and rainfall. Altitude:-   The height of a locationabove mean sea level is called altitude. Usually mesured in meteres or feet. The mean sea level is considered zero. 3. Layers of the Atmosphere (i) Troposphere Height: 0–12 km Weather changes occur here. Contains air, clouds and water vapour. Temperature decreases with height. Trop...

 Chapter 2: Shaping of the Earth's Surface –  https://drive.google.com/file/d/1Guq-qwATmy_VrVWZiGnVp3tTUHam-U47/view?usp=drive_link 1. Introduction:-  What Shapes the Earth's Surface? The Earth's surface is not fixed. It is continuously changing due to the action of powerful internal and external forces. Two Main Types of Forces A. Internal (Endogenic) Forces:- These forces originate inside the Earth. They cause: Formation of mountains Earthquakes Volcanoes Folding and faulting B. External (Exogenic) Forces:- These forces act on the Earth's surface. They include: Weathering Erosion Deposition They slowly wear down and reshape landforms. Why is this chapter important?  Understanding the Earth's surface helps us: Explain earthquakes and volcanoes. Understand how mountains and plains are formed. Identify disaster-prone regions. Appreciate the dynamic nature of the Earth. 2. Plate Tectonics:-  Plate Tectonics is a theory proposed by W. J. Morgan that explains the m...

 Chapter 3: Forests, Biodiversity and Livelihoods Biodiversity (जैव विविधता):- Biodiversity refers to the variety of all living organisms found on Earth, including plants, animals, fungi, and microorganisms, along with the ecosystems they form. Simple Definition:-  The variety of life in a particular area or on Earth is called biodiversity. Examples: A forest containing trees, birds, insects, mammals, and microorganisms. Different types of plants and animals found in a national park. Importance: Maintains ecological balance. Provides food, medicine, fuel, and raw materials. Supports livelihoods and healthy ecosystems. 2. Genetic Diversity (आनुवंशिक विविधता):-  Genetic diversity refers to the variation in genes among individuals of the same species. Simple Definition:-  Differences in characteristics among members of the same species due to differences in their genes. Examples: Different varieties of rice, wheat, and mango. Different breeds of dogs. Humans with diffe...

Chapter - 2  Disaster Preparedness and Regulatory Frameworks "In the word 'DISASTER', the letter 'D' refers to a situation in which destruction occurs, causing things in the surroundings to be destroyed or disappear." "In the word 'DISASTER', the letter 'D' stands for destruction, a situation where things around us are damaged, destroyed, or disappear." Cyclone:-  A cyclone is a large-scale weather system characterized by strong winds rotating around a center of low atmospheric pressure. Cyclones are usually accompanied by heavy rainfall, thunderstorms, and strong winds that can cause widespread damage. Why Do Cyclones Occur:-  Cyclones form over warm ocean waters due to the following conditions: Warm Sea Surface Temperature – The ocean water should be at least 26.5°C or higher. Low-Pressure Area – Warm air rises from the ocean surface, creating a low-pressure zone. Moisture in the Air – Rising warm air carries moisture, which condens...