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प्रश्न
Write scientific reason.
Sodium metal is kept in kerosene.
उत्तर
Sodium metal is kept in kerosene because sodium is a very reactive metal. It is kept in kerosene to prevent it from coming in contact with oxygen and moisture. If this happens, it will react with the moisture present in air and form Sodium hydroxide. This is a strongly exothermic reaction, and a lot of heat is generated. It will result out in the form of fire.
संबंधित प्रश्न
Give an example of a metal which is a liquid at room temperature.
Fill in the blanks:
Phosphorus is a very _________ non-metal.
Write the balanced chemical equation to prepare ammonia gas in the laboratory by using an alkali.
Name the non-metal which is used to preserve food materials.
Name the non-metal which is used in the vulcanisation of rubber.
Which property of iron metal is utilised in producing iron sheets required fro making buckets?
What is the nature of the oxide SO2? What happens when it is dissolved in water? Write the chemical equation of the reaction involved.
State one use of Sulphur.
State three reasons (of which at least one must be chemical) for believing that sodium is a metal.
The electronic configurations of four particles A, B, C and D given below:
| A | 2, 8, 8 |
| B | 2, 8, 2 |
| C | 2, 6 |
| D | 2, 8 |
Which electronic configuration represents:
(i) magnesium atom?
(ii) oxygen atom?
(iii) sodium ion
(iv) chloride ion?
Name a metal used as a thermometric liquid
Name a non-metal that is used to kill germs in water
Give reasons
Tungsten is used in electric bulbs.
Give four differences between metals and non-metals with reference to their:
- Melting point and boiling point
- The conductivity of heat and electricity
- Malleability
- Solubility
Statements given below are incorrect. Write the correct statements :
Soda water is prepared by dissolving washing soda in water.
Match the statements in Column A, with those in Column B .
| Column A | Column B | ||
| 1 | A metal used for making high quality mirrors . | a | Chlorine |
| 2 | A metal which neither malleable nor ductile. | b | Graphite |
| 3 | A non-metal,used in the sterilsation of water. | c | Iodine |
| 4 | A non-metal, whose deficiency can lead to disease like goitre. | d | Silver |
| 5 | A non -metal which can be used as dry lubricant. | e | Zinc |
Write ‘True’ or ‘False’ in front of following statement.
Graphite is used in making filaments of electric bulb.
Write ‘True’ or ‘False’ in front of following statements.
Non-metals are poor conductors of electricity.
Gold and silver are used to make jewellery. Give reason
Name the following:
An Alloy of copper and Zinc.
With reference to the physical properties of metals and non-metals, state the following exception.
A metal which floats on water.
Select the appropriate option for the following statement:
The element which is noble gas and radioactive in nature.
Select the appropriate option for the following statement:
The element which is a noble metal.
_______ is basic oxide.
Identify who I am!
Carbon allotropes- _______
Name six common non-metals and write their symbols.
Non-metals are non-malleable.
Match the following:
| 1. | Non-metals | a. | Silicon |
| 2. | Metals | b. | fire extinguisher |
| 3. | Metalloids | c. | dull and soft |
| 4. | Oxygen | d. | hard and shiny |
| 5. | Water | e. | supports fire |
