Class 8 Science Lesson 4 Inside Question

Class 8 Science Lesson 4 Inside Question and Answer NCERT & CBSE Board Here in this post. NCERT Class 8 Science Textbook Lesson 4 Inside Questions.

Grade: VIII

Lesson 4 Materials : Metals And Non-Metals.

Que. 1) fill in the blanks .

(1) The properties of metal by which it can be drawn into wires is called—–

Ans- Ductility.

(2) Non –metals are —-  conductors of heat and —–

Ans- bad , electricity.

(3) The sulphrous acid turns —- litmus paper into —-

Ans- blue , red

Que. 2) answer the following questions.

(1) Define malleability .

Ans- The property of metals by which they can be beaten into thin sheets is called Malleability.

(2) Define ductility.

Ans- the property of metal by which it can be drawn into wires is called ductility.

(3) Give difference between metals and non – metals.

Ans-

Metals

Non- metals

Metals are the good conductor of electricity.

Non-metals are bad conductor of electricity.
Metals are malleable, ductile ,sonorous and good conductors of heat.

Non- metals are non malleable, non ductile and bad conductors of heat.

For example- aluminium, copper, calcium, magnesium etc

For example-carbon, oxygen, phosphorous etc.


(4) Explain displacement reaction with example.

Ans- the displacement of metals of one reaction to another reaction are called as displacement reaction. In the displacement reaction more reactive metal can replace by less reactive metal ,but a less reactive one cannot replace by more reactive one. For example- CuSO4 + Zn – ZnSO4 + Cu in this reaction zinc is more reactive than copper iron so it replaces the copper iron.

(5) Give uses of metals and  non-metals.

Ans- there are various uses of metals and  non- metals in our daily life. Metals are used in making machinery , automobailes, aeroplanes, trains, satellites, industrial gadgets, cooking utensils, water boilers etc.  similarly non- metals are also used in fertilizers to enhance the growth of plants, non-metals are also used in water purification process, they are also used in purple cloured solution which is applied on wounds as an antiseptic , non-metals are also used in crackers. Etc are the different uses of metals and non- metals.

(6) Why sodium is stored in kerosene.

Ans- sodium metal is very reactive. It reacts vigorously with oxygen and water. A lot of heat is generated in the reaction therefore it is stored in kerosene.

(7) Phosphorous stored in water, why?

Ans- generally non-metals are stored in water. Phosphorous is a non –metals. It is a very reactive non-metal. It catches fire if exposed to air. To prevent the contact of phosphorous with atomospheric oxygen it is stored in water.

Updated: December 19, 2020 — 2:03 am

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