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प्रश्न
A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?
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उत्तर
Iron nails are attracted by magnet. Thus, they can separated from saw dust using magnetic separation.
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संबंधित प्रश्न
Match the following
| Column A | Column B | ||
| (a) | Molecules | (i) | Water boils |
| (b) | 100° C | (ii) | Evaporation |
| (c) | 0° C | (iii) | Changes from solid to gas |
| (d) | At all temperatures | (iv) | Matter |
| (e) | Camphor | (v) | Water freezes |
Which one is a kind of matter:
What is the scientific name of particles which make up mater?
Name a non-metal which is a good conductor of electricity.
What is meant by saying that metals are malleable and ductile ?
What is meant by saying that non-metals are brittle ?
What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur ?
Fill in the following blanks with suitable words :
An element is made up of only one kind of ........
Which of the following is not an element ?
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 ?
Define solvent.
One of the following does not show Tyndall effect. This one is :
One of the following liquids will leave behind a residue on heating. This one is :
Which technique is used in a washing machine to squeeze out water from wet clothes while drying ?
Describe the method of separating a mixture containing common salt, sand and ammonium chloride.
Tincture of iodine is a mixture of two materials X and Y. The material Y has a property that its solid form can be converted directly into vapours on heating by a process called Z.
- What could X be ?
- What could Y be ?
- Name the process Z.
- Which process would you use to recover both the components X and Y from tincture of iodine ?
- Which process can be used to recover only component Y from tincture of iodine ?
______ is not made of matter.
Gases change to liquid by the process of ______.
Boiling refers to the process by which a substance changes from the liquid to the gaseous state at its ______ point.
Define the term matter.
