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प्रश्न
Name the terms for the change of vapour into a liquid.
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उत्तर
Condensation .
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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 non-metal which is a good conductor of electricity.
Name a metal which is yellow in colour.
Which of the following is not an element ?
Define Aerosol Give one example.
Which of the following are chemical changes and which physical ? Give reason.
- a glass bottle breaking
- coal burning in air
- making a cake
- wool being knitted into a sweater
When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.
(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A. Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.
State whether the following statement are true or false :
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.
Name the source from which nitrogen and oxygen are obtained on a large scale.
What is the general name of the process by which tea-leaves are separated from prepared tea ?
You are given a mixture of iodine in alcohol called tincture iodine. Which method will you use to recover both, iodine as well as alcohol, from this mixture ?
Name one pair of liquids which can be separated by using a separating funnel.
Explain the meaning of the term ‘matter’.
Complete the given analogy.
Murukku from hot oil: ______:: Coffee powder residue from decoction: ______
Diffentiate between absorption and adsorption.
What type of matter glass is?
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
A teabag placed in a cup of hot water will diffuse into the water.
Define the term matter.
