Question

Q. 4] Solve any one from the following questions

1] Read the following paragraph and answer the

questions based on it. 5

The phenomenon of existence of a substance in

various physical forms but the same chemical form is

known as allotropy. Both diamond and graphite are

formed by carbon atoms. Diamond is a hard,

beautiful crystalline substance while graphite is a

soft, grayish black crystalline substance. In diamond,

each carbon atom is linked to four other

neighbouring carbon atoms held the corners of aregular tetrahedron by covalent bonds to form a

rigid three dimensional structure. In case of graphite,

each carbon atom is attached to three other carbon

atoms forming a hexagonal planar structure. Physical

properties of graphite and diamond are different but

their chemical properties are the same. In diamond,

there are no mobile electrons in the system and hence

a diamond crystal is a non-conductor of electricity.

On the other hand, in graphite, free electrons move

throughout the entire layers and hence graphite is a

good conductor of electricity.

Uses : Diamond is used as a precious stone in

jewellery. Black diamonds are used for cutting glass,

while graphite is used in making electrodes and

carbon, lubricants and lead pencils.

i) What is allotropy?​

Answer 1

Answer:The phenomenon of existence of a substance in various physical forms but the same chemical form is known as allotropy. Explanation:

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