EVERYDAY SCIENCE

Detailed explanation-1: -Extrusive, or volcanic, igneous rocks are formed when molten hot material cools and solidifies. There are three main types of rocks: sedimentary, igneous, and metamorphic. Each of these rocks are formed by physical changes-such as melting, cooling, eroding, compacting, or deforming-that are part of the rock cycle .

Detailed explanation-2: -CLASSIFICATION The classification of rocks is based on two criteria, TEXTURE and COMPOSITION. The texture has to do with the sizes and shapes of mineral grains and other constituents in a rock, and how these sizes and shapes relate to each other. Such factors are controlled by the process which formed the rock.

Detailed explanation-3: -Igneous rocks are formed from melted rock deep inside the Earth. Sedimentary rocks are formed from layers of sand, silt, dead plants, and animal skeletons. Metamorphic rocks formed from other rocks that are changed by heat and pressure underground.

Detailed explanation-4: -Based on formation, rocks are classified into three categories-Igneous, Sedimentary and Metamorphic.

Detailed explanation-5: -When the molten material, known as magma within the crust and lava on the surface, cools down, it solidifies giving rise to rocks. These are known as igneous rocks. As these rocks are formed out of the material from the interior of the earth, these are also referred to as primary rocks.