Advertisements
Advertisements
प्रश्न
Name two processes which provide the best evidence for the motion of particles in matter.
Advertisements
उत्तर
Diffusion and Brownian motion, provide the best evidence about the random motion of particles in matter.
APPEARS IN
संबंधित प्रश्न
Intermolecular force of attraction is maximum in ............ less in .......... and the least in .............
Out of solids, liquids and gases, which one has :
- maximum movement of particles ?
- maximum interparticle attractions ?
- minimum spaces between particles ?
Fill in the following blank with suitable words :
The best evidence that the particles of matter are constantly moving comes from the studies of ................. and ...................
Name the scientist who studied the movement of pollen grains suspended in water through a microscope. What is this phenomenon known as?
What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur ?
The three important metalloids are.............................. and ..........................
What are the two types of pure substances? Give one example of each type.
Name a metal which can be easily cut with a knife.
Which of the following is not an element ?
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 ?
Fill in the following blank :
Milk is a .................... solution but vinegar is a .................... solution.
What is a suspension ? Give two examples of suspensions.
What is a colloid ? Give two examples of colloids (or colloidal solutions)
100 mL of water at room temperature of 25°C is taken in a beaker and a little of solid S is dissolved in it by stirring to obtain a solution X. More and more of solid S is added to the solution with constant stirring, while keeping the temperature of solution constant at 30°C. After some time it is observed that no more solid dissolves in water and at the same time some solid is also left undissolved at the bottom of the beaker.
- The contents of beaker are filtered through a filter paper to obtain solution Y in the form of a filtrate.
- What name is given to solutions like X ?
- What name is given to solutions like Y ?
- What will you observe if the solution Y at 30°C is cooled down to 10°C by keeping the beaker in crushed ice ? Why ?
- What term is used to denote the amount of solid dissolved in 100 grams of water in a solution lie Y ?
How will you separate iron pins from sand ?
Why wires cannot be drawn from materials such as stone or wood?
Define the term matter.
Define the term matter.
