Question

Which non-metal is used for making lead pencils?
(A) Lead
(B) Graphite
(C) Zinc
(D) Charcoal

Answer 1

Hint: As we know that non-metals like carbon were used to make pencil lead by mixing it with clay in very old times. But now industries use an allotrope of carbon and mix it with the clay to make the lead of the pencils. So here we have to tell the non-metal is used for making lead of pencils.

Complete answer:
Let us discuss about carbon and its allotropes as follows:-
-Carbon and its allotropes: Carbon is a chemical element denoted by symbol ‘C’ and has atomic number 6. It has +4 valence due to 4 valence electrons in its outermost shell. Due to its tetravalency and catenation property, carbon has the ability to Form various allotropes.
-The famous allotropes of carbon are diamond and graphite. Both of them have completely different properties as diamond does not conduct electricity whereas graphite is a good conductor of heat and electricity. Diamond is very hard but graphite is not hard enough as it can easily be crushed. This is all due to the different arrangement of carbon atoms in their structures.
-Graphite mineral is generally found in igneous and metamorphic rocks. It is formed when carbon is subjected to very extreme temperature and pressure inside the earth’s crust. It is used in manufacturing writing materials such as lead of pencils or slates where the lead is made through a mixture of clay and graphite that is in amorphous form. It is used in nuclear reactors to control the nuclear reaction and also used to develop graphene sheets.
-So from the above data we can say that the non-metal used for making lead pencils is (B) Graphite.

Note:
-Carbon is one of the most important elements on earth and has various uses in chemistry. So remember to study about carbon and its allotropes along with its properties and uses to solve these types of questions easily.
-Also graphite is used in nuclear reactions because it can absorb the neutrons and stop the reaction from being uncontrollable.