The Earth Class 5th EVS Question Answers

Ans. Earlier, it was thought that earth was formed from a rotating body of hot gases in space. These gases after getting cooled form the earth and other bodies.
Later, in about 1990, it was suggested that the earth was formed out of material from the sun. It is believed it was fiery hot at the beginning. Later on, after millions of years went by, the earth becomes cooler and a thin layer called crust is formed which sealed the heat inside it.

Ans. The three main layers of the earth are:
a) Crust
b) Mantle
c) Core
a) Crust: It is the outermost layer of the earth. Its thickness varies from place to place. Under continents, its thickness ranges from 35 to 60 kilometres while under the oceans it is only 6 kilometres.
b) Mantle: It is the middle layer of the earth and is about 2900 km thick. It is made up of rocks which are in a semi-molten state.
c) Core: The innermost part of the earth is called the core. The inner region of the core is a solid ball made up of iron and nickel. The outer region of the core has metals present in the molten state.

Ans. The mountains are formed by the movement in the earth’s crust and it takes millions of years to form a mountain. The earth’s crust gets squeezed and forms fold mountains. There are two types of mountains.
Block Mountains: They are formed when the earth’s crust splits and one side is pushed up.
Dome Mountains: They are formed when melted rock below the earth’s crust slowly forces the land upwards.

(i) Volcano: The melted rock, steam and ashes that are forced through a hole in the surface, may form a mountain called a volcano.
(ii) Earthquake: Earthquakes occur when large masses of rocks slip past each other suddenly. Great trembling and vibrations are often felt. These shocks can be so strong that they destroy buildings and do great damage. However, some earthquakes are so mild that they are not noticed.
(iii) Solar Eclipse: When the moon comes between the sun and the earth, it blocks some sunlight from the earth, and the solar eclipse takes place. It forms a small shadow on the earth.
(iv) Lunar Eclipse: When the earth comes between the sun and moon, a lunar eclipse takes place. During the lunar eclipse, the moon comes in the shadow of the earth.

Ans. The spinning of the earth on its axis is called the rotation of the earth. It takes 24 hours for the earth to complete one rotation on its axis. Rotation of earth forms day and night.

Ans. The movement of the earth on its axis around the sun is called the revolution of the earth. Earth takes 365 days and 6 hours to complete one revolution. It is called one solar year. Revolution of the earth forms seasons.

Ans. The four imaginary lines on the globe are:
1. Axis
2. The Equator
3. Tropic of Cancer
4. Tropic of Capricorn

Ans. It is an imaginary line around the sun which passes through the centre of the earth and divides the earth into two halves.
It is very hot near the equator because the sun’s rays fall directly on the equator throughout the year.

Ans. The rotation of the earth causes the formation of day and night.

Ans. There are two factors which cause a change in the seasons. These are:
1. The tilted axis of the earth.
2. The revolution of the earth.

Ans. Eclipse is nothing but the partial or complete hiding of one heavenly body by another by its shadow. There are two types of the eclipse: Solar eclipse and Lunar eclipse.