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प्रश्न
Explain why, diamond can be used in rock drilling equipment but graphite cannot.
उत्तर
As diamond is extremely hard, it can be used to cut and grind other hard materials or metals. Hence, it is used in rock-drilling equipment to drill holes in the rocky layers of the Earth. Graphite being soft cannot be used to cut or grind.
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संबंधित प्रश्न
State the reason to explain why covalent compounds "have low melting and boiling points."
Choose the correct answer from the options given below:
Which of the following is a common characteristic of a covalent compound?
1) high melting point
2) consists of molecules
3) always soluble in water
4) Conducts electricity when it is in the molten state
Choose the most appropriate answer from the following list of oxides which fit the description.
A covalent oxide of a metalloid.
Buckminsterfullerene is spherical molecule in which 60 carbon atoms are arranged in interlocking hexagonal and pentagonal rings of carbon atoms.
How many hexagons of carbon atoms are present in one molecule of buckminsterfullerene?
What type of bonds are present in H2 molecule? Draw their electron-dot structures.
will CS2 conduct electricity or not?
give reason for your choice.
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)
Explain why, diamond is hard while graphite is soft (though both are made of carbon atoms).
Write two points of difference in the structures of diamond and graphite.
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
Observe the straight chain hydrocarbons given below and answer the following
questions :
i) Which of the straight chain compounds from A and B is saturated and unsaturated straight chains?
ii) Name these straight chains.
iii) Write their chemical formulae and number of – CH2 - units.
Acids dissolve in water to produce positively charged ions. Draw the structure of these positive ions.
Draw an electron dot diagram to show the formation of the following compound.
Magnesium chloride [ H=1, C=6, Mg=12, Cl=17].
Draw the electron dot structure of covalent compound methane (non polar) and HCL (polar) and give two difference between them.
Name two compounds that are covalent when taken pure but produce ions when dissolved in water.
The number of electrons in the valence shell of a carbon atom is 4.
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
| \[\begin{array}{cc} \phantom{..}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\ \phantom{..}|\phantom{....}|\phantom{....}|\\ \ce{H - C - C- C- H}\\ \phantom{.}|\phantom{....}|\phantom{....}|\\ \ce{H - C - H}\\ |\\\ce{H}\end{array}\] |
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
 |
It is observed that covalent compounds are had conductors of electricity. Give reason.
