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प्रश्न
Name two solid, two liquid and two gaseous elements at the room temperature.
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उत्तर
Aluminium and copper are two elements that are solid at room temperature. Both bromine and mercury are liquid at room temperature. Nitrogen and hydrogen are two elements that are gaseous at room temperature.
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संबंधित प्रश्न
Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
Name two processes which provide the best evidence for the motion of particles in matter.
Honey is more viscous than water. Can you suggest why?
Define matter. Give four examples of matter.
During respiration, glucose and oxygen enter our body cells and waste products carbon dioxide and water leave the body cells by the process of :
Name a liquid which can be classified as a pure substance and conducts electricity.
Which of the following are not compounds ?
Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond
Classify the following into elements, compounds and mixtures :
arble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk
In the following set of substances, one item does not belong to the set. Select this item and explain why it does not belong to the set :
Hydrogen, Oxygen, Steam, Chlorine
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
Choose the correct answer.
A 5 per cent sugar solution means that :
State whether the following statement is true or false :
Sponge is an example of solid sol.
What is chromatography ? State its two applications.
The material which is added to water during purification process at the water works so as to disinfect it is :
A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with
cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the
process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And
S is a white solid which is used in making ordinary dry cells.
- What could P, Q, R and S be ?
- How would you separate a mixture containing P, Q, R and S ?
Differentiate between the-two characteristics of matter – ‘mass’ & ‘weight’.
______ is not made of matter.
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
Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and are coloured.
Name a non-metal which exists as a liquid at room temperature.
The fluidity of solids: ______.
