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प्रश्न
Fill in the following blank with suitable words :
The best evidence that the particles of matter are constantly moving comes from the studies of ................. and ...................
उत्तर
The best evidence of the particles of matter are constantly moving comes from the studies of diffusion and Brownian motion.
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संबंधित प्रश्न
Differentiate between an atom and a molecule.
Define the following term of Matter .
In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?
Fill in the following blanks with suitable words :
An element is made up of only one kind of ........
Classify the following into elements and compounds :
- H2O
- He
- Cl2
- CO
- Co
Which of the following are ‘pure substances’ ?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air
What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.
Name a metal which has a low melting point.
Which of the following is a sol ?
Shaving cream, Milk, Fog, Soap solution, Hairspray
Classify the following into true solutions and colloidal solutions:
Ink, Salt solution, Starch solution, Blood, Sugar solution
What is the effect of temperature on the solubility of solids in liquids ?
Fill in the following blanks with suitable words :
Miscible liquids are separated by .....................
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 ?
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 ?
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 ?
Name one pair of liquids which can be separated by using a separating funnel.
Asmita went to buy an earthen pot. There she saw many things kept for sale.
How did she identify what she needed?
Which among the following is not a matter?
Complete the following table:
| S.No. | CELSIUS | KELVIN |
| 1. | 90°C | 363 K |
| 2. | ______ | 283 K |
| 3. | 63 °C | ______ |
| 4. | 250°C | ______ |
| 5. | ______ | 303 K |
Write a scientific reason.
Lemon sherbat has a sweet, sour and salty taste and it can be poured in a glass.
