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प्रश्न
Select the correct answer from A, B, C, D & E for the statement given below :
A metalloid.
विकल्प
Gunpowder
Iodine
Boron
Helium
Bromine
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उत्तर
A metalloid: Boron
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संबंधित प्रश्न
Match the columns.
| column A | column B |
|
1. to separate grain from chaff |
a. filtration |
| 2. to saparate sawdust from water | b. sedimentation and deeantation |
| 3. to separate iodine from sodium chloride | c. winnowing |
| 4. to separate iron fillings from sand | d.sublimation |
|
5. it is used to separate sand and water |
e maganetic separation |
|
|
f .handpicking |
What is the difference between a pure substance and a mixture ?
Give three differences between metals and non-metals.
Tick (√) the correct alternative from the choice given for the following statement
A gaseous non-metal.
‘The modern periodic table consists of elements arranged according to their increasing atomic numbers’. With reference to elements with atomic numbers 1 to 20 only in the periodic table – differentiate them into – metallic elements, metalloids, non-metals & noble gases.
Match the separation of components in List I with the most appropriate process in List II.
| List I | List II |
| 1. Naphthalene from naphthalene & sodium chloride. | A: Separating funnel |
| 2. Cream from milk. | B: Sublimation |
| 3. Kerosene oil from kerosene oil & water. | C: Boiling |
| 4. Lead nitrate from an aqueous solution of lead nitrate. | D: Centrifugation |
| 5. Ammonia from an aqueous solution of ammonia. | E: Distillation |
Select the correct answer from the choice given below to complete the sentence :
Compounds are ____________ in nature.
Select the correct answer from the choice given below to complete the sentence :
An example of a monoatomic molecule is ___________.
Give a reason for the following statement :
Brass & bronze are examples of mixtures, while copper sulphate & lead nitrate are examples of compounds.
Reason out
Elements are called semimetals.
