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प्रश्न
What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain during Brownian motion.
उत्तर
The zigzag movement of the small particles suspended in a liquid or a gas is called Brownian motion.
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संबंधित प्रश्न
Liquids have definite shape and definite volume.
Which one is a kind of matter:
Define matter. Give four examples of matter.
Which of the following are ‘pure substances’ ?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air
Which of the following are compounds ?
- CO
- No
- NO
- Co
State whether colloidal solutions are homogeneous or heterogeneous.
How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
How will you differentiate between a suspension and a colloid ?
What is a suspension ? Give two examples of suspensions.
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.
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Name the process you would use to separate a mixture of water and alcohol.
Name the process by which common salt is purified.
Fill in the following blanks with suitable words :
The separation of liquids by fractional distillation is based on the difference in their .....................
Explain how, impure copper sulphate can be purified by crystallisation.
Pure copper sulphate can be obtained from an impure sample by the process of :
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 ?
Stars including Sun are covered in ______.
Atoms or groups of atoms having a charge are called ______.
Evaporation is always accompanied by ______ in temperature.
