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प्रश्न
Fill in the following blanks with suitable words :
An element is made up of only one kind of ........
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उत्तर
An element is made up of only one kind of atoms.
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संबंधित प्रश्न
A kind of matter which can sublime is
State two characteristics of matter demonstrated by Brownian motion.
What is meant by saying that non-metals are brittle ?
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
Give reason why copper metal is used for making electric wires.
Which of the following are compounds ?
- CO
- No
- NO
- Co
The property/properties which enable copper metal to be used for making electric wires is/are :
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 ?
What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?
If 25 mL of acetone is present in 150 mL of its aqueous solution, calculate the concentration of solution.
In what respects does a true solution differ from a colloidal solution ?
Describe the various steps involved in the separation of iodine, iron filings and salt from a mixture.
Explain the meaning of the term ‘matter’.
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
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.
Liquids have ______.
Higher the temperature, the higher the kinetic energy of particles.
Solids do not flow.
Evaporation does form bubbles.
Write a scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
