NCERT Solutions for Chapter 7 Rocks and Minerals Class 5 Science 

Short Notes for Class 5 Science Chapter 7 Rocks and Minerals

The earth's crust is made up of rocks, which are natural masses of mineral matter. Rocks can be classified as igneous, sedimentary, or metamorphic. Inside the earth, there is a fiery hot substance known as magma. Minerals are found in igneous rocks, such as granite and basalt. Minerals have distinct chemical and physical properties, compositions, and atomic structures. As a result of geological processes, rocks are generally made up of two or more minerals.

NCERT Solutions for Class 5th Science Chapter 7 Rocks and Minerals

Rocks and Minerals Questions and Answers

Chapter Name

Rocks and Minerals NCERT Solutions

Class

CBSE Class 5

Textbook Name

Science

Related Readings



Question 1: Name the three layers of the earth.

Answer: The three layers of the earth are:

  1. Crust
  2. Mantle
  3. Core - Outer core, Inner core


Question 2: Name the three types of rocks with one example each.

Answer: The three types of rocks are:

  1. Igneous rock-pumice
  2. Sedimentary rock - shale
  3. Metamorphic rock - marble


Question 3: What are metamorphic rocks? How are they formed?

Answer: Rocks that have changed their form over time are called metamorphic rocks. They are formed due to physical and chemical changes in igneous, sedimentary, or older metamorphic rocks themselves due to heat and pressure.


Question 4: What are minerals? Give any three examples of minerals.

Answer: All rocks are made up of substances called minerals. Minerals are chemics substances that occur in nature. Eg: gold, silver and iron.


Question 5: What are magnets? Mention the two types of magnets with examples.

Answer: Magnets are the substances that can attract objects made up of iron, cobalt and nickel. There are two types of magnets:

  1. Natural magnets: These are found in nature and these are made up of a mineral called magnetite.
  2. Man-made: These are made by man from iron, cobalt and nickel.


Question 6: Name the different types of igneous rocks. Describe any two.

Answer: The different types of igneous rocks are:

  1. Granite
  2. Obsidian
  3. Pumice

Obsidian:

  1. It is smooth and glassy and is formed by quick cooling of lava.
  2. It is used in making jewellery and ornaments.
  3. It is usually black or dark coloured.

Pumice:

  1. It is porous, or full of holes is formed from lava that is frothy with a lot of air within it.
  2. It is the only rock that can float.
  3. It is used in making light weight materials like concrete blocks.


Question 7: How are sedimentary rocks formed? Name the different types of

sedimentary rocks. Describe any one.

Answer: Sedimentary rocks are formed by repeated deposition of rocks particles that are worn away from mountains by winds and water.

The different types of sedimentary rocks are:

  1. Conglomerate
  2. Sandstone
  3. Shale
  4. Limestone

Shale:

  1. It is made up of solidified clay apart in thin layers.
  2. It is used in making bricks and cement.


Question 8: What are the different types of metamorphic rocks? Describe any two.

Answer: The different types of metamorphic rocks are:

1.Marble

  1. Slate
  2. Gneiss
  3. Quartzite

Slate:

  1. It is formed from shale a sedimentary rock.
  2. Like shale, it splits into flat layers.
  3. It is used in making brick and cement.

Gneiss:

  1. It is formed from granite.
  2. It has different kinds of minerals in it<< giving it a striped or streaked look.
  3. It is used as building stone.


Question 9: Describe the various uses of rocks and minerals.

Answer:

Uses of rocks are:

  1. Rocks are used as building material for making schools, houses, roads and bridges. Some rocks are used in their original form while some are used to make bricks, cement, tar and concrete. For eg: granite, limestone, sandstone and marble.
  2. Rocks give us useful metals for eg meals like iron, copper and aluminum are used for making utensils and precious metals like gold, platinum are used for making jewellery.
  3. Rocks give us fuel for eg: coal is used for producing electricity, heating and moving nuclear energy.
  4. Rocks are used as gemstones for eg: diamond, ruby, sapphire and emerald are used for making jewellery because when they are polished they appear shiny and beautiful.

Uses of minerals:

  1. Minerals like Sulphates and Nitrates are used as fertilizers because they help the plant to grow.
  2. Minerals are a very important part of our diet. For eg: minerals like calcium, sodium and iron are required for the healthy functioning of our body.


Question 10: Continuous heating and cooling breaks even a hard rock into small pieces of sand. What should we learn from this process?

Answer: This process teaches us that no matter how hard we are but with regular practice and hard work and guidance of our elders we can become a fine human being.


Question 11: How does heat and pressure of earth contribute to the formation of metamorphic rocks?

Answer: Heat and pressure of the earth can change the physical or chemical composition of igneous or sedimentary rocks and leads to the formation of metamorphic rocks.


Question 12: Can we find fossils in the granite or marble mines? Why?

Answer: We can find fossils in the granite or marble mines because it is formed from sedimentary rocks which can have fossils in them during their formation.


Question 13: What is the difference between magma and lava.

Answer: The difference between magma and lava is:

  1. Magma: Molten rock inside the earth is called magma.
  2. Lava: Molten magma that flows out onto the surface of the earth is called lava.


Question 14: Name the important minerals that are found in igneous rocks.

Answer: The important minerals that are found in igneous rocks are:

  1. Mica
  2. Feldspar
  3. Magnesium

 

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