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प्रश्न
Select the correct answer from the choice in the bracket.
The least reactive metal.
विकल्प
magnesium
silver
copper
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उत्तर
silver
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संबंधित प्रश्न
Write true or false
All pure substances have characteristic melting and boiling points.
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 |
Give Two Examples for Each of the Following: Inert Gases
Why is it necessary to separate the constituents of a mixture.
Name: a Liquid Metal
Define: Molecule
Name: Three different forms of carbon
Give one use of the following substance:
Iron
Give one use of the following substance:
Coal
Fill in the blank
A metal which is a poor conductor of electricity is _______.
Indicate whether the following statement is true or false:
Ozone is a triatomic molecule
Tick (√) the correct alternative from the choice given for the following statement.
Sugar is a compound which consists of the elements
Tick (√) the correct alternative from the choice given for the following statement.
Brass and bronze are
Classify substances into pure and impure substances in the form of a chart or tabulation.
Select the correct answer from the choice given below.
The element which is malleable
Match the compounds in List I – 1 to 20 with their correct formulas from in List II-A to T.
| List I | List II | ||
| 1 | Hydrochloric acid | A | NaCI |
| 2 | Potassium Hydroxide | B | NaOH |
| 3 | Sulphuric Acid | C | KCI |
| 4 | Zinc Hydroxide | D | Ca(OH)2 |
| 5 | Sodium Chloride | E | CaS |
| 6 | Nitric Acid | F | CuSO4 |
| 7 | Calcium Hydroxide | G | CaCO3 |
| 8 | Carbonic Acid | H | NH4CI |
| 9 | Sodium hydroxide | I | HCI |
| 10 | Copper sulphate | J | ZnO |
| 11 | Potassium Chloride | K | HNO3 |
| 12 | Calcium Carbonate | L | H2CO3 |
| 13 | Magnesium Sulphide | M | MgS |
| 14 | Zinc Sulphate | N | MgO |
| 15 | aluminium Hydroxide | O | KOH |
| 16 | Sodium Carbonate | P | ZnSO4 |
| 17 | Calcium Sulphide | Q | Na2CO3 |
| 18 | Magnesium Oxide | R | H2SO4 |
| 19 | Zinc Oxide | S | AI(OH)3 |
| 20 | Ammonium Chloride | T | Zn(OH)2 |
Give a reason for the following statement:
Components in a mixture are present in varying proportions and not in a fixed proportion.
Classify the substances given in Fig. 2.2 into elements and compounds
How are elements classified?
Give the chemical formula for cane sugar.
