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प्रश्न
Give reasons
Magnesium is used in fire works.
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उत्तर
Magnesium is used in fire works because it bums with a dazzling light.
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संबंधित प्रश्न
Give reasons for the following.
Copper cannot displace zinc from its salt solution.
Fill in the following blanks with suitable words:
A metal having low melting point is ..................... but a non-metal having very high melting point is ..............
The atomic number of an element X is 12.
(a) What must an atom of X do to attain the nearest inert gas electron configuration?
(b) Which inert gas is nearest to X?
Name two alloys of iron. What elements are present in these alloys?
Mention two uses of the following metals and non-metals
Oxygen
A metal which is neither ductile nor malleable is
State the position of the following in the periodic table:
Iron and zinc
Write scientific reason.
Generally the ionic compounds have high melting points.
Write scientific reason.
Sodium is always kept in kerosene.
With reference to the following metals state their use in daily life metal:
copper
State why telegraph poles are painted with aluminium paint.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A white crystalline solid which decrepitates on heating leaving a residue which fuses with the glass and evolves two gases one of which is coloured and acidic.
Aluminium: _______: gold : : electric insulator
Halogen reacts with acid.
Electronic configuration of metal A is 2,8,1. Electronic configuration of metal B is 2,8,8,2. Which of the above metals is more reactive? Explain with reason.
Higher Order Thinking Skills.
Aakash noticed that the metal latch on gate was difficult to open during hot sunny days. However, it was not difficult to open the same latch at night. Aakash observed that the latch and the gate are exposed to the sun during day time.
- Formulate a hypothesis based on the information provided.
- Briefly state how you would test the hypothesis.
Which of the following metals are obtained by electrolysis of their chlorides in molten state?
- Na
- Ca
- Fe
- Cu
Name two soft metals which can be cut with a knife.
Sodium is a hard metal.
Why are metalloids called semimetals?
