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प्रश्न
Name a metal which has no fixed shape.
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उत्तर
Mercury has no fixed shape.
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संबंधित प्रश्न
Which of the following materials fall in the category of a “pure substance”?
- Ice
- Milk
- Iron
- Hydrochloric Acid
- Calcium oxide
- Mercury
- Brick
- Wood
- Air
What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain during Brownian motion.
When extremely small particles X derived from the anther of a flower were suspended in a liquid Y and observed through a microscope, it was found that the particles X were moving throughout the liquid Y in a very zig-zag way. It was also observed that warmer the liquid Y, faster the particles X moved on its surface.
- What could particles X be ?
- What do you think liquid Y is ?
- What is the zig-zag movement of X known as ?
- What is causing the zig-zag movement of particles X ?
- Name the scientist who discovered this phenomenon.
- What does this experiment tell us about the nature of liquid Y?
Name the property which allows metals to be hammered into thin sheets.
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
State two physical properties on the basis of which metals can be distinguished from non-metals.
The elements which normally exist in the liquid state are :
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.
Choose the correct answer.
A 15% alcohol solution means :
Fill in the following blank :
Milk is a .................... solution but vinegar is a .................... solution.
Define Aerosol Give one example.
21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solubility of sodium chloride in water at that temperature.
Define solubility of a substance. How does it vary with temperature ?
What is a colloid ? Give two examples of colloids (or colloidal solutions)
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
What difference in the property of two miscible liquids enables their separation by fractional distillation ?
Explain how, impure copper sulphate can be purified by crystallisation.
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 ?
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
The fluidity of solids: ______.
