CBSE Class 11 Geography Chapter 8 Composition and Structure of Atmosphere Notes
Atmosphere is the huge blanket of air that surrounds the earth and provides life supporting conditions on the earth.
The main constituents of air are nitrogen, oxygen, carbon dioxide, argon, helium, ozone, hydrogen, water vapour and dust particles.
Nitrogen constitutes the largest proportion of the atmosphere. It accounts for 78.03% of the total volume of gases.
Oxygen is the life giver gas of the atmosphere. It accounts for 20.99% of total volume of gases in air. Carbon dioxide is the heaviest gas of the atmosphere. It forms about 0.036% volume . Please refer Class 11 Geography Chapter 8 Composition and Structure of Atmosphere Notes for more information.
CBSE Class 11 Geography Chapter 7 Landforms and their Evolution Notes
The geomorphic agents like running water, ground water, wind, glaciers and waves form different landforms on the earth. These geomorphic agents acting over long periods of time produce systematic changes, leading to sequential development of landforms. The running water in its different stages, forms erosional and depositional landforms like valleys, Potholes, Plunge pools, incised or entrenched meanders, river terraces, alluvial fans, deltas, floodplains, natural levees and point bars, meanders and braided channels. The process of formation of landforms by the action of groundwater is called Karst topography. Please refer Class 11 Geography Chapter 7 Landforms and their Evolution Notes for more information.
CBSE Class 11 Geography Chapter 6 Geomorphic Processes Notes
Geomorphic processes refer to the chemical and physical interaction between the earth’s surface and the natural forces acting on it. This interaction produces various landforms. Geomorphic processes can be classified into exogenic and endogenic processes.
Endogenic forces are generated in the interior of the earth. Endogenic processes can be classified into diastrophic and sudden movements. Diastrophic forces can be classified into epeirogenic and orogenic forces. Sudden forces comprise of earthquake and volcanic eruptions. Exogenic forces are the forces generating outside the earth’s surface. These forces can be classified into o weathering, mass movement, erosion and deposition. Please refer Class 11 Geography Chapter 6 Geomorphic Processes Notes for more information.
CBSE Class 11 Geography Chapter 5 Minerals and Rocks Notes
Minerals are naturally occurring substance. Minerals are formed through geological processes and are found in various forms in nature. They are also obtained from rocks. The study of minerals is called ‘Mineralogy’. Minerals generally occur in igneous, sedimentary, and metamorphic rocks. Minerals are usually found in the raw form or ‘ores’. The site of excavating the ore or mineral is called a ‘Mine’. Minerals are broadly classified into: metallic, non-metallic and energy minerals. Metallic minerals are further classified into: ferrous and non-ferrous minerals. The major minerals produced in India are Iron-ore, copper, bauxite, mica, coal l, natural gas, and petroleum. Energy resources are classified into conventional and non-conventional energy resources. Please refer Class 11 Geography Chapter 5 Minerals and Rocks Notes for more information.
CBSE Class 11 Geography Chapter 4 Distribution of Oceans and Continents Notes
Alfred Wegener, a German meteorologist put forth “the Continental Drift Theory” in 1912. About 300 years ago, all the continents formed a single continental mass. The super continent was named ‘Pangaea’, which meant ‘all earth’. A mega ocean surrounded ‘Pangaea’, which was called ‘Panthalassa’, meaning ‘all water’. Pangaea began to break up into two large continental masses called Laurasia and Gondwanaland. Laurasia and Gondwanaland continued to break into land masses, which look similar to our modern-day continents. Please refer Class 11 Geography Chapter 4 Distribution of Oceans and Continents Notes for more information.
CBSE Class 11 Geography Chapter 3 Interior of the Earth Notes
Earth is a dynamic planet. The surface of the earth is visible to us, but how can we know about the interior of the earth? There are direct and indirect sources to study about the interior structure of the earth. Direct sources include volcanic eruptions, mining areas and drilling projects. The indirect sources on the other hand include analysis of the properties of matter, like temperature, pressure and density of material. Some of the other indirect sources include meteors, gravitation, magnetic field and seismic activity. Please refer Class 11 Geography Chapter 3 Interior of the Earth Notes for more information.
CBSE Class 11 Geography Chapter 2 The Origin and Evolution of the Earth Notes
Earth and the other celestial bodies in the solar system has always been a subject of fascination for all of us. People, since the early times were eager to know about the origin of Earth and the evolution of life on it. The research to find the age of Earth started long back. A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of Earth. Early theories include: Nebular Hypothesis Revised Nebular Hypothesis Planetesimal Hypothesis of Chamberlin and Moulton Tidal Hypothesis of Jeans and Jaffreys Modern theories are: Big Bang Theory Hoyle’s Concept of Steady State The distributed matter in the universe came together due to the gravitational forces and formed the galaxies. A galaxy contains a large number of stars, which are formed from the clumps of gas developed in the nebula. Please refer Class 11 Geography Chapter 2 The Origin and Evolution of the Earth Notes for more information.
CBSE Class 11 Geography Chapter 1 Geography as a Discipline
Geography is the description of the earth. The term geography was first coined by Eratosthenes. It is derived from two roots from the Greek language: Geo meaning earth and graphos meaning description. Scholars defined Geography as the description of the earth as the abode of human beings. Geography draws its subject matter from the natural sciences and social sciences. It is a synthesis of both and acts as an integrating discipline. Please refer Class 11 Geography Chapter 1 Geography as a Discipline Notes for more information.
The term geography was first devised by Eratosthenes, a Greek scholar (276-194 BC.). Geography is a discipline of the combination of spatial synthesis and temporal synthesis. According to geography, Earth is described as the abode of human beings. Landforms provide the foundation on which anthropogenic activities are placed. The plains are used for agriculture. Plateaus provide a platform for minerals and forest. Mountains make available space for meadows, forests, tourist spots, etc. They are regarded as the sources of rivers. Please refer Class 11 Geography Notes for more information.
An index number is not an absolute measure, it measures the percentage change in a variable over time. It does so by comparing the value of a variable at present to its value at a base year. Index number gives a quantitative foundation to qualitative statements like prices are falling or rising. Lastly, index numbers show changes in average. In effect, it means if the average change is 5% then some goods might not change exactly at 5%. Please refer Statistics for Economics Class 11 Notes Chapter 8 for more information.
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