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प्रश्न
Fill in the following blank :
A colloid is a ..............mixture and its components can be separated by the technique known as ...............
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उत्तर
A colloid is a heterogeneous mixture and its components can be separated by the technique known as centrifugation.
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संबंधित प्रश्न
Give one difference between atoms and molecules.
What are the two conditions for the interconversion of states of matter ?
Name the scientist who studied the movement of pollen grains suspended in water through a microscope. What is this phenomenon known as?
Name a non-metal which is a good conductor of electricity.
Fill in the following blanks with suitable words :
An element is made up of only one kind of ........
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
Name a non-metal :
- which is lustrous
- which is required for combustion
- whose one of the allotrophic forms is a good conductor of electricity. Name the allotrope.
- other than carbon which shows allotropy
- which is known to form the largest number of compounds
Which of the following statements are true for pure substances ?
- pure substances contain only one kind of particles
- pure substances may be compounds or mixtures
- pure substances have the same composition throughout
- pure substances can be exemplified by all elements other than nickel
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 ?
Milk of Magnesia is :
Name the process by which common salt is obtained from sea-water.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
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Which one of the following scrap metal cannot be separated by magnetic separation ?
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Name one pair of liquids which can be separated by using a separating funnel.
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 |
Atoms are tiny particles that repel each other when they are squeezed very close.
Examples of foam are ______.
Define the term matter.
