Tungsten wire is used in electric bulbs. - Science and Technology 1

Short Note

Tungsten wire is used in electric bulbs.



The melting point of tungsten is extremely high. To emit light, the filament of a bulb must be heated to extremely high temperatures. As a result of its high melting point, tungsten is used.

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.................... liberated when acetic acid reacts with sodium metal.
(a) Hydrogen
(b) Chlorine
(c) Oxygen
(d) Nitrogen

A solution of CuSO4 in water is .................... in colour.
(a) Pink
(b) Blue
(c) Colourless
(d) Green

Metal A has electronic configuration (2, 8, 1) and metal B has (2, 8, 8, 2). Which is more reactive? Why? Identify these metals.

_________ solution is blue in colour.
(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3

Iron is
(a) More reactive than zinc
(b) More reactive than aluminium
(c) Less reactive than copper
(d) Less reactive than aluminium

‘E’ is an element which reacts with oxygen to form an oxide E2O. An aqueous solution of E2O turns red litmus blue, so:
i. What is the nature of oxide E2O ?
ii. Write the name of element ‘E’.

Write equations for the reactions of iron with steam 

What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.

The solution of Aluminium sulphate in water is .....................

(a) Green

(b) Colourless

(c) Pink

(d) Blue

The reaction of an iron nail with copper sulphate solution is ........... reaction.

(a) Combination

(b) Displacement

(c) Double displacement

(d) Decomposition

A solution of _________________ in water is green in colour.

(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3

Write equation for the reaction of sodium with oxygen.

Complete and balance the following equation:

Cu (NO3)2 (aq)  +  Zn(s)  →


Why does aluminium not react with water under ordinary conditions?

Why is white phosphorus kept immersed under water?

Out of the following oxides, the amphoteric oxide is:
(a) Fe2O3
(b) Al2O3
(c) P2O5
(d) N2O

In nature, metal A is found in a free state while metal B is found in the form of its compounds. Which of these two will be nearer to the top of the activity series of metals?

Choose the correct alternative and rewrite the following:

Reaction of iron nails whith copper sulphate solution is an example of _____________________

Choose the correct alternative and rewrite the following:

Which of the following is lue in colour?

Write the chemical equation of the above process.

Answer the following question:
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is metal or a non - metal. Explain with a proper example. 

Which property of metals is used for making bells and strings of musical instruments like Sitar and Violin?

A cable manufacturing unit tested few elements on the basisof their physical properties.

Properties W X Y Z
Malleable Yes No No Yes
Ductile Yes No No Yes
Electrical conductivity Yes Yes Yes No
Melting Point High Low Low High

Which of the above elements were dicarded for usage by the company?

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?

Which of the following property is not responsible for copper to be used as electrical conduction wires?

Find the odd one out:


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