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प्रश्न
Write a few lines on the blackboard with a chalk. Now observe the chalk. What changes do you see in the chalk?
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उत्तर
The chalk reduces in size after writing on the blackboard. It becomes flat on the side from which we use it for writing.
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संबंधित प्रश्न
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
Name a metal which is soft and a non-metal which is hard.
What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.
“Is malleable and ductile” best describes :
9.72 g of potassium chloride dissolves in 30 g of water at 70°C. Calculate the solubility of potassium chloride at that temperature.
Name the process by which common salt is obtained from sea-water.
Explain how, nitrogen , oxygen and argon gases are separated from air.
Which of the following mixture cannot be separated by using water as the solvent ?
Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compounds or mixtures
(iii) Pure substances have the same composition throughout
(iv) Pure substances can be exemplified by all elements other than nickel
