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प्रश्न
Why is graphite a good conductor of electricity but diamond is a non-conductor of electricity?
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उत्तर
Graphite is a good conductor of electricity because of the presence of free electrons in its crystal. As we know that an atom of carbon has 4 valence electrons, in a graphite crystal, each carbon atom is connected to only three other carbon atoms by covalent bonds. This means that the fourth valence electron of each carbon atom is free. These free moving electrons are responsible for the conduction of electricity in a graphite crystal. But in the case of diamond these free electrons are not available due to its structure. Hence, diamond is a non-conductor.
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संबंधित प्रश्न
Elements forming ionic compounds attain noble gas configuration by either gaining or losing electrons from their outermost shells. Give reason to explain why carbon cannot attain noble gas configuration in this manner to form its compounds.
State whether the following statement is true or false:
Diamond and graphite are the covalent compounds of carbon element (C)
Fill in the following blank with suitable word:
The form of carbon which is known as black lead is ...........
Give the formula of the compound that would be formed by the combination of the following pair of elements:
K and H
Using electron-dot diagrams which show only the outermost shell electrons, show how a molecule of oxygen, O2, is formed from two oxygen atoms. What name is given to this type of bonding? (At. No. of oxygen = 8)
Two non-metals combine with each other by the sharing of electrons to form a compound X.
(a) What type of chemical bond is present in X?
(b) State whether X will have a high melting point or low melting point.
(c) Will it be a good conductor of electricity or not?
(d) Will it dissolve in an organic solvent or not?
A solid element X has four electrons in the outermost shell of its atom. An allotrope Y of this element is used as a dry lubricant in machinery and also in making pencil leads.
(a) What is element X?
(b) Name the allotrope Y.
(c) State whether allotrope Y is a good conductor or non-conductor of electricity.
(d) Name one use of allotrope Y (other than lubrication and pencil leads)
(e) Name two other allotropes of element X.
Define a covalent bond.
Elements forming ionic compounds attain noble gas electronic configuration by either gaining or losing electrons from their valence shells. Explain giving reason why carbon cannot attain such a configuration in this manner to form its compounds. Name the type of bonds formed in ionic compounds and in the compounds formed by carbon. Also explain the reason why carbon compounds are generally poor conductors of electricity.
Draw an electron dot structure of the following molecule. (Without showing the circle) :
Ethene
Explain the following briefly:
Sodium chloride dissolves in water but carbon tetra chloride is insoluble in water.
What is the term defined below?
A bond formed by a shared pair of electrons, each bonding atom contributing one electron to the pair.
State the type of bonding in the following molecule.
Water
What are the term defined below?
A bond formed by share pair of electrons, each bonding atom contributing one electron to the pair.
Explain the following:
Polar covalent compounds conduct electricity?
Covalent bonds can be single, double or triple covalent bonds. How many electrons are shared in each? Give an example of each type.
The number of pi-bonds present in benzoic acid molecule are ______.
When ethyl alcohol and acetic acid are mixed, the resulting ester has a chemical formula ______.
Molecular reactions are ______ in the covalent compound.
Non-polar covalent compounds are ______ conductors of heat and electricity.
