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प्रश्न
State whether the following statement is true or false :
Bread is an example of solid foam.
विकल्प
True
False
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उत्तर
True. Solid foam allows the gas to get dispersed in solid medium.
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संबंधित प्रश्न
The inter-molecular space is maximum in
Fill in the blank :
The state of matter with definite volume and definite shape is called______
What are molecules ?
Which type of elements, metals or non-metals, show the property of brittleness ?
Classify the following into elements and compounds :
- H2O
- He
- Cl2
- CO
- Co
Classify the following as elements or compounds :
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea
Name a metal which is yellow in colour.
There is a large group of materials P which can be divided into three groups Q, R and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.
- What could the group of materials P be ?
- Name the substances Q. Give two examples of such substances.
- Name the substances R. Write two examples of such substances.
- Name the substances S. Give two examples of such substances.
- Out of Q, R and S, which substances are malleable and ductile ?
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 ?
Explain what happens when a beam of light is passed through a colloidal 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
Name the property of one of the constituents which can be used to separate a mixture of salt and iodine
Name the process by which common salt is purified.
Fill in the following blanks with suitable words :
If a mixture contains iron filings as one of the constituents, it can be separated by using a .......................
The given mixture contains three constituents A, B and C. The constituent A is a yellow coloured, solid element which dissolves in a liquid D. The constituent B is a blue coloured salt which is insoluble in liquid D but dissolves easily in another liquid E. The constitudent C is a liquid which is used in cooking food and forms a solid fat on hydrogenation.
(a) What do you think could (i) constituent A, and (ii) liquid D be ?
(b) What could (i) constituent B, and (ii) liquid E be ?
(c) What could liquid C be ?
(d) How will you separate the mixture containing A, B and C ?
Select the correct answer from A, B, C, D & E for the statement given below:
An atom or group of atoms _________ having a resultant charge.
Name the metals that are used in jewellery.
Atoms or groups of atoms having a charge are called ______.
The phenomenon of Evaporation takes place at the ______ of a liquid.
Define the term matter.
