Last updated on June 28th, 2023 at 11:06 pm
Some rocks are used as fuels, such as coal, natural gas, and petroleum, while hard rocks are used to construct buildings and roads.
The shiny and precious properties of some rocks make them suitable for jewelry making. Soft rocks are used for talcum powder, chalk, etc.
Que – What are metamorphic rocks?
The rocks that have been formed by the conversion of igneous and sedimentary rocks under intense pressure and heat are called metamorphic rocks.
Tick the correct answer.
(i) The rock which is made up of molten magma is
- Igneous
- Sedimentary
- Metamorphic
(ii) The innermost layer of the earth is
- Crust
- Core
- Mantle
(iii) Gold, petroleum, and coal are examples of
- Rocks
- Minerals
- Fossils
(iv) Rocks that contain fossils are
- Sedimentary rocks
- Metamorphic rocks
- Igneous rocks
(v) The thinnest layer of the earth is
- Crust
- Mantle
- Core
Match the following
| Core | Earth’s surface |
| Minerals | Used for roads and buildings |
| Rocks | Made of silicon and alumina |
| Clay | Has the definite chemical composition |
| Sial | Innermost layer |
| Changes into slate | |
| Process of transformation of the rock |
Give reasons.
We cannot go to the center of the earth.
We cannot reach the center of the earth because it has incredibly high temperatures and pressures, and lies 6000 km below the ocean floor. Due to the lack of oxygen and unfavorable conditions, we would not be able to survive there.
Sedimentary rocks are formed from sediments.
When rocks roll down, crack, and hit one another, they break down into smaller fragments. These smaller fragments are called sediments. These sediments are transported and deposited by wind and water. These loose sediments are compressed and hardened to form layers of rocks. These rocks are called sedimentary rocks.
Limestone is changed into marble.
Since limestone is a sedimentary rock, it is changed into marble under intense pressure and heat.
