Rocks
Rocks play an important role in the formation of soil. Soil is formed because of weathering and decomposition of rocks. Rocks also contain many minerals.
Geography Class 9
Earthquakes
Earthquakes may occur when disturbances are produced by the deposition of sediments by rivers and glaciers on the ocean floor.
Our World – The Solar System
A large cluster or collection of stars held together by gravitational force along with gases and dust is known as a galaxy.
The Atmosphere
The blanket of air which surrounds the Earth is known as the atmosphere. It exists in several layers. The atmosphere is made of many gases and solid particles.
Precipitation
The water cycle includes the process of evaporation, condensation and precipitation. The heat of the Sun evaporates the water resulting in the formation of water vapour.
Weathering
Weathering is the gradual wearing and tearing of rocks on the surface of the Earth. The main agents of weathering are temperature, humidity and precipitation.
Volcanoes
A volcano is a vent or an opening in the Earth’s crust from which hot magma erupts from the interior of the Earth. Volcanoes are generally caused because of the following reasons:
Landforms of the Earth
The surface of the earth is not the same everywhere. The earth has an infinite variety of landforms. Some parts of the lithosphere may be rugged and some flat.
The Earth’s Grid
The framework formed by the intersection of the latitudes and longitudes on the Earth is known as a geographic grid. It helps us to locate exact places on the globe.
Rotation and Revolution
The spinning of the Earth on its axis is known as rotation, The revolution of the Earth around the Sun in an elliptical orbit is revolution.