Telangana SCERT Class 8 Physical Science Chapter 4 Solution – Metals and Non Metals. Here in this post we provides Class 8 Physical Science Metals and Non Metals Telangana State Board Solution. Telangana State Board English Class VIII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telangana State Board Class 8 Physical Science Chapter 4 Metals and Non Metals Solution:
(1) Explain about ductility.
Ans: – The property of drawing a material to make fine wires is called ductility. Most metals are ductile. If any object is ductile it can be stretched into wire.
These objects also can hammer into thin wires.
(2) Explain the physical properties of metals with suitable examples.
Ans: – Metal after posses all of the following physical properties. They are lustrous, hard, malleable, ductile, good conductors of heat and electricity and sonorous.
Lustrous: – The materials which have a bright surface and reflect light are called lustrous materials.
Examples: – Aluminium
Sonority: – Materials which produce ringing sound are called sonorous materials. This materials when hit the hard floor and got sound.
Example: Zink, Copper.
Malleability: – The materials which can be flattend into thin sheets are called malleable materials.
Example: – Metals like aluminium, silver, and gold are highly malleable.
Ductility: – The property of drawing a material to make fine wires is called ductility.
Examples: – Iron
Good conductors of electricity: – Materials that allow electricity to pass through them and bulb to glow are called electricity conductors.
Example: – Iron, copper, aluminium.
Good conductors of that: – Mainly all metals conduct heat. But all materials do not have equal conductivity.
Example: – Iron, Copper and aluminium cooking vessels are preferred due to their high heat conductivity.
(3) Gold jewellery does not become dull. Why?
Ans: – Gold is lustrous in nature and Gold does not react with components in air, so they did not get moistures.
So gold jewellery does not become dull.
(4) Draw the diagram of identifying electric conductivity of a material.
Ans: –
Diagram of identify electric conductivity of a material.
(5) Which gas makes a Pop Sound when it exposed to lighted match stick?
Ans: – Hydrogen gas makes a pop sound when it exposed to lighted match stick.
Application of concepts
(1) If you are given two samples, how do you distinguish which one is metal and which is non metal?
Ans: – In this twi samples in which one have been seen all these following properties like –
(i) If they are good conductors of heat and electricity.
(ii) They are malleable
(iii) They are ductile
(iv) They have high melting point
(v) High density or if they show lustrous.
Then we can decide this one is metal.
But when we have not been seen all these properties then this one is called non metal.
Non metal properties are –
(1) They are non malleable, non ductile,
(2) They don’t show lustrous
(3) They are bad conductors of heat and electricity
(4) Low density and low melting point in them.
(2) Which metals are used in making jewellary? Why?
Ans: – Gold, Silver and Platinum are some of the metals used in making jewellary.
Because all these metals are very less reactive metal and also don’t react with the elements which present in atmosphere/air.
Gold and platinum are such metals which do not rust.
Platinum, gold and silver are sued to make jewellary because of their bright shiny surface and have high malleability and ducting.
(3) Why cooking pans don’t have metal handles?
Ans: – Because the metal is a good conductor of heat. So the handles get heated very fast and when we try to hold it may we get hurt our hands. For this reason cooking pans don’t have metal handles. They are made up of plastics or fibres which are bad conductors of heat.
(4) How do you appreciate the efforts of man to use the Metals in making tools?
Ans: – I appreciate them because metals are very useful for us. The early man discovered this metal. Now a day’s almost all products we are using in our daily life are made up of inetals.
Metals are useful us in many ways, Metals will help for making many materials like school bells, Metals also make wires to conduct electricity. So metals are very useful for us. So the efforts of man that made our life so simple and easy and also change our usual life. Man made metals things like wheel, cooking, bowls etc…. that make our life beautiful.
(5) Why the bells are made by metals instead of wood?
Ans: – Wood is not sonorous and also wood is not metal. But the bells are made by metals because metals are sonorous, and they make a ringing sound. Due to this properly of the metals a loud metallic. Sound is occurred when we hit a metal piece by any objects.
Higher Order Thinking Questions
(1) You came to know that the Diamond is a hardest material and it is a non metal and similarly Mercury is a soft material and it is a metal. Write down the questions raised in your mind.
Ans: – Question are –
(1) Why is a metal soft and a non metal hard?
(2) Why dimond is a non metal, as it has a luster?
(3) Why diamond is a non metal, still it hardest materials?
(4) How mercury is a metal, Still it so sof material?
(5) How and which way can we classify metals and non metals
(3) In a chemical reaction iron is unable to displace Zinc from Zinc Sulphate. Why?
Ans: – In a chemical reaction, a more reactive metal can replace a less reactive metal from its solution. Here iron is less reactive as compared to that means zine is more reactive than iron. So this is Because of its property, it can be made into different shapes. So it can also used in railway coaches, tracks, making in thin wires. Aluminium also used to make aluminium sheet, foil paper, which is essential for packing food, It is also used for making Jewellary / ornaments etc.
Multiple Choice Questions:
(1.) Sulphur dioxide , by nature is –
Ans. (b) Acidic Oxide.
(2) Maximum metals are obtained in the state of-
Ans. (b) Solid.
(3) Some metals react with acids and evolve-
Ans. Hydrogen.
(4) Generally non metallic oxides are by nature-
Ans. Acidic
(5) The property of changing the metals into sheets is known as-
Ans. Malleability.