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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
Match the substances given in Column A with their uses given in Column B.
| A | B | ||
| 1 | Gold | a | Thermometers |
| 2 | Iron | b | Electric wire |
| 3 | Aluminium | c | Wrapping food |
| 4 | Carbon | d | Jewellery |
| 5 | Copper | e | Machinery |
| 6 | Mercury | f | Fuel |
Why is ammonia gas not collected over water?
Which property of copper and aluminium makes them suitable for making cooking utensils and boilers?
Name two metals which are used for making domestic utensils and factory equipment.
You are given a dry cell, a torch bulb with holder, wires and crocodile clips. How would you use them to distinguish between samples of metals and non-metals?
Name two physical properties of sodium in which it's behaviour is not as expected from it's classification as metal.
Name a non-metal having lustre (shining surface).
The electronic configurations of three elements A, B and C are as follows:
| A | 2, 8, 1 |
| B | 2, 8, 7 |
| C | 2, 4 |
(a) Which of these element is a metal?
(b) Which of these elements are non-metals?
(c) Which two elements will combine to form an ionic bond?
(d) Which two elements will combine to form a covalent bond?
(e) Which element will form an anion of valency 1?
Fill in the blank
A chemical compound that makes up the striking heads of match sticks is ______
Statements given below are incorrect. Write the correct statements :
Chlorine gas is used in the manufacture of sulphuric acid.
Name the non-metal and its natural form, which is the hardest substance.
Name a non-metal whose compounds help in the growth of plants.
Define metal and non-metal on the basis of electron loss or gain.
Name a liquid non-metal.
Select from the following ist:
`Fe_2O_3, , NO, PbO, Mn_2O_7`
Acidic oxide ………………
Name:
Two metals which are liquid at room temperature
Name two metals which react with cold water.
Explain how the activity series accounts for each of the following:
reaction with acids
Give the balanced reactions for the following:
Iron reacts with dilute HCI
How many valence electrons are present in:
(i) metals and
Explain the term Gangue .
Name the following:
or
With reference to the physical properties of metals and non-metals, state the following exception.
A metal which is liquid at room temperature.
From the list of characteristics given below, select the five which are relevant to non-metals and their compounds:
- Ductile
- Conduct electricity
- Brittle
- Acidic Oxides
- Basic Oxides
- Discharged at anode
- Discharged at cathode
- Ionic chlorides
- Covalent chlorides
- Reaction with dilute sulphuric acid yields hydrogen
- 1, 2 or 3 valence electrons
- 5, 6, 7 valence electrons
(Write the five letters corresponding to the correct characteristics).
Differentiate between metals and non-metals with reference to –
(a) number of electrons in outer or valence shell
(b) formation of cation and anion
(c) reaction with dilute acids.
Give a reason why – properties of metals are related to their activity or reactivity series of metals. Explain the same with reference to potassium and iron in the series.
Complete the statement given below, by filling in the blank with the correct word:
A non-metal that leaves a mark on paper _______
Give reason for the following:
Metals form cations while non-metals form anions.
State whether the statement given below is true or false. If false write the correct statement.
The chemical name of rust is iron [III] oxide.
