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प्रश्न
The three important metalloids are.............................. and ..........................
उत्तर
The three important metalloids are boron, silicon, and germanium.
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संबंधित प्रश्न
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Define the following term of Atom .
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 ...................
Explain why air is used to inflate tyres.
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
- swelling up of a raisin on keeping in water
- spreading of virus on sneezing
- earthworm dying on coming in contact with common salt
- shrinking of grapes kept in thick sugar syrup
- preserving of pickles in salt
- spreading of smell of cake being baked in the kitchen
- aquatic animals using oxygen dissolved in water during respiration
What is meant by saying that metals are malleable and ductile ?
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 ?
Choose the correct answer.
A 15% alcohol solution means :
In what respects does a true solution differ from a colloidal solution ?
What is the difference between colloids and suspensions ?
Name the process by which the various gases of the air are separated.
Fill in the following blanks with suitable words :
A mixture of kerosene and petrol can be separated by .....................
How will you separate camphor, common salt and iron nails from their mixture ?
Tincture of iodine is a mixture of two materials X and Y. The material Y has a property that its solid form can be converted directly into vapours on heating by a process called Z.
- What could X be ?
- What could Y be ?
- Name the process Z.
- Which process would you use to recover both the components X and Y from tincture of iodine ?
- Which process can be used to recover only component Y from tincture of iodine ?
Explain the meaning of the term matter with special reference to the term ‘substance’.
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 ?
Asmita went to buy an earthen pot. There she saw many things kept for sale.
How did she identify what she needed?
Which among the following ______ will get attracted to by magnet?
Diffentiate between absorption and adsorption.
Atoms are tiny particles that repel each other when they are squeezed very close.
