General Science 5th Class Chapter 8 Structure of the Earth Solved Exercise

General Science

5th Class

Chapter 8

Structure of the Earth

Questions

1. Encircle the correct option.

i. The outer layer of the Earth is called:

a. external core        b. mantle        c. crust        d. inner core

ii. What are the main types of the soil?

a. silt, sand and rock        b. clay, humus and sand

c. sand, silt and clay        d. silt, humus and clay

iii. Which type of soil is good for growth of plants?

a. sand        b. silt        c. clay        d. rock

iv. What is the role of living organisms in the soil?

a. making soil soft and airy        b. making soil hard

c. making soil unfit for cultivation        d. making the air dry

v. The amount of fresh water on the Earth is:

a. about 1%        b. about 30%        c. about 70%        d. about 97%

vi. What is important in the natural manure?

a. minerals        b. the decayed matter        c. sand        d. salts

2. Write short answers.

i. What is the outer layer of the Earth called? What is its importance in our life?

Ans.

The outer layer of the earth is called crust. It is that part on the earth where we live. This part contains mountains, deep oceans, rivers, deserts, green fields, rural and urban dwellings.

ii. Which soil is useful to make pottery? What are its properties?

Ans.

Clay is used to make pottery.

Properties: The wet clay can be moulded into any shape. It retains its shape when dried and becomes more harder.

iii. Which matter is obtained from decayed plants and insects?

Ans.

Humus, a decayed matter is obtained due to decomposition of plants and insects.

iv. What part of the Earth's surface consists of oceans? Why can we not drink sea water?

Ans.

The 71% of the earth surface is covered by water. About 97% is the salted water in the oceans, we can not drink sea water due to dissolved salts.

v. Where is the water found in the form of solid, liquid and gas (vapours)?

Ans.

Water is found on earth in three states of matter. In solid form, it is found in mountain and glaciers. In liquid state, it is found in rivers and lakes, while in vapour phase it exists as clouds.