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प्रश्न
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.
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उत्तर
(a) The solid element 'X' is carbon, which has four electrons in the outermost shell of its atom.
(b) Graphite is the allotrope 'Y' of carbon which is used as a dry lubricant in machinery, and al in making pencil leads.
(c) Graphite (Y) is a good conductor of electricity because of the presence of free electrons in its crystal.
(d) Graphite (Y) is used in making carbon electrodes or graphite electrodes in dry cells and electric arcs.
(e) Diamond and buckminsterfullerene are the two other allotropes of carbon.
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संबंधित प्रश्न
What are covalent compounds?
What would be the electron-dot structure of carbon dioxide which has the formula CO2?
What type of bonds are present in Cl2 molecule? Draw their electron-dot structures.
Fill in the blank in the following sentence:
The number of single covalent bonds in C2H2 molecule are ...........
What type of bond is present in oxygen molecule?
What type of chemical bond is present in chlorine molecule? Explain your answer.
Explain the formation of a chlorine molecule on the basis of electronic theory of valency.
Explain why, graphite can be used as a lubricant but diamond cannot.
The number of isomers formed by the hydrocarbon with molecular formula C5H12 is:
(a) 2
(b) 5
(c) 3
(d) 4
State the type of bonding in the following molecule.
Water
Give two example in following case:
Gaseous non polar compounds
Distinguish between ionic and covalent compounds under the following properties:
(i) Strength of forces between constituent elements
(ii) Solubility of compounds in water
(iii) Electrical conduction in substances
The covalent bond in which the electrons are shared equally between the combining atoms.
Draw an electron dot diagram to show the formation of the following compound.
Magnesium chloride [ H=1, C=6, Mg=12, Cl=17].
Compound X consists of molecules.
Choose the letter corresponding to the correct answer from the options A, B, C and D given below:
X is likely to have a ______.
Draw the electron dot diagram and structure of nitrogen molecule.
The molecular masses of a carbon compound spread over a range of _______.
From the following hydrocarbon _______ is the cyclic hydrocarbon.
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
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Mineral acids are stronger acids than carboxylic acids because
- mineral acids are completely ionised
- carboxylic acids are completely ionised
- mineral acids are partially ionised
- carboxylic acids are partially ionised
