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प्रश्न
The smallest unit of matter that exists freely in nature is called ...........
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उत्तर
The smallest unit of matter that exists freely in nature is called molecule.
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संबंधित प्रश्न
When a crystal of potassium permanganate is placed at the bottom of water in a beaker, the water in the whole beaker turns purple on its own, even without stirring. This is an example of :
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
- swelling up of a raisin on keeping in water
- spreading of virus on sneezing
- earthworm dying on coming in contact with common salt
- shrinking of grapes kept in thick sugar syrup
- preserving of pickles in salt
- spreading of smell of cake being baked in the kitchen
- aquatic animals using oxygen dissolved in water during respiration
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
- What type of substance could X be ? Name one substance like X.
- What type of substance could Y be ? Name one substance like Y.
- What type of substance could Z be ? Name one substance like Z.
- Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
- Name the three groups into which all the substances like Y are divided on the basis of their properties.
Define solute.
How will you differentiate between a suspension and a colloid ?
Milk of Magnesia is :
What difference in the property of two miscible liquids enables their separation by fractional distillation ?
Explain the meaning of the term matter with special reference to the term ‘substance’.
Rusting of an article made up of iron is called
Define the term matter.
