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प्रश्न
Name two processes which provide the best evidence for the motion of particles in matter.
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उत्तर
Diffusion and Brownian motion, provide the best evidence about the random motion of particles in matter.
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संबंधित प्रश्न
Fill in the blank
All matter is made up of tiny particles called ______
Which of the following materials fall in the category of a “pure substance”?
- Ice
- Milk
- Iron
- Hydrochloric Acid
- Calcium oxide
- Mercury
- Brick
- Wood
- Air
What are the conditions for 'something' to be called 'matter'?
What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.
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
Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
- What type of substance is B ?
- What type of substance is C ?
- Name the gas (i) D, and (ii) E ?
- State one characteristic property of gas D.
- Write one test to identify gas E.
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 ?
What happens when the temperature of a saturated sugar solution is increased ?
Classify the following into true solutions and colloidal solutions:
Ink, Salt solution, Starch solution, Blood, Sugar solution
Define solubility of a substance. How does it vary with temperature ?
What is meant by a solution?
One of the following is a solid foam. This one is :
The solubility of ammonium chloride in water at various temperatures is given below :
| Temperature | : | 10°C | 20°C | 40°C | 60°C | 80°C |
| Solubility | : | 24 g | 37 g | 41 g | 55 g | 66 g |
What mass of ammonium chloride would be needed to make a saturated solution of ammonium chloride in fifty grams of water at 40°C ?
Fill in the following blanks with suitable words :
The separation of liquids by fractional distillation is based on the difference in their .....................
Naphthalene can be separated from sand :
Asmita went to buy an earthen pot. There she saw many things kept for sale.
What is the difference between a substance and an object?
All the matter made of ______.
Liquids cannot be compressed and they have fixed volume.
Atoms are tiny particles that repel each other when they are squeezed very close.
