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प्रश्न
Explain why steel is used to make railway lines.
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उत्तर
Steel is used to make railway lines because the particles of steel have fixed positions and show no free movement. This ensures that there will be no change in the shape of the railway lines, which makes it safe to travel.
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संबंधित प्रश्न
Define the following term of Atom .
What is the scientific name of particles which make up mater?
Name a non-metal :
- which is lustrous
- which is required for combustion
- whose one of the allotrophic forms is a good conductor of electricity. Name the allotrope.
- other than carbon which shows allotropy
- which is known to form the largest number of compounds
Which of the following are compounds ?
- CO
- No
- NO
- Co
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
In what respects does a true solution differ from a colloidal solution ?
Define Foam Give one example.
Name the source from which nitrogen and oxygen are obtained on a large scale.
Explain how, nitrogen , oxygen and argon gases are separated from air.
Which of the following cannot be separated from air by the process of fractional distillation ?
The boiling point of liquid argon is :
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Explain the meaning of the term matter with special reference to the term ‘substance’.
Write a few lines on the blackboard with a chalk. Now observe the chalk. What changes do you see in the chalk?
Which among the following is not a matter?
Which statement is not correct for a mixture
Evaporation does form bubbles.
Gas-solid is ______.
Give an example of liquid in gas.
Define the term matter.
