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प्रश्न
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
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उत्तर
- Elements: An element is a substance made up of one type of atom.
(a) sodium, (d) silver, (f) tin, (g) silicon - Compounds: A compound is a substance made up of two or more types of atoms that are chemically bonded together to form molecules.
(e) Calcium carbonate, (k) methane, (j) soap, (l) carbon dioxide - Mixtures: A mixture is a combination of substances that are not chemically bonded together.
(c) Sugar solution, (b) soil, (i) air, (h) coal, (m) blood
संबंधित प्रश्न
Define the following term of Atom .
Which one is a kind of matter:
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 :
Fill in the following blanks with suitable words :
The elements which are sonorous are called ..........................
What elements do the following compounds contain ?
Sugar, Common salt
“Is malleable and ductile” best describes :
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 15% alcohol solution means :
Classify the following into true solutions and colloidal solutions:
Ink, Salt solution, Starch solution, Blood, Sugar solution
Which of the following are chemical changes and which physical ? Give reason.
- a glass bottle breaking
- coal burning in air
- making a cake
- wool being knitted into a sweater
Which of the following represents the solubility of sugar in water at 20°C ?
Which one of the following is not a chemical change ?
How will you separate a mixture of common salt, sulphur powder and sand ?
Which of the following mixture cannot be separated by using water as the solvent ?
If there is a sudden shower, we take shelter under a roof at the roadside. Even though the rain does not fall on us directly, we get wet to some extent. Why ?
The property which allows the metals to be hammered into their sheets is ______.
Match the physical quantities given in column A to their S I units given in column B:
| (A) | (B) | ||
| (a) | Pressure | (i) | cubic metre |
| (b) | Temperature | (ii) | kilogram |
| (c) | Density | (iii) | pascal |
| (d) | Mass | (iv) | kelvin |
| (e) | Volume | (v) | kilogram per cubic metre |
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 |
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
