Advertisements
Advertisements
प्रश्न
An element E exists in three allotropic forms A, B and C. In allotrope A, the atoms of element E are joined to form spherical molecules. In allotrope B, each atom of element E is surrounded by three other E atoms to form a sheet like structure. In allotrope C, each atom of element E is surrounded by four other E atoms to form a rigid structure.
(a) Name the element E.
(b) What is allotrope A.
(c) What is allotrope B?
(d) What is allotrope C?
(e) Which allotrope is used in making jewellery?
(f) Which allotrope is used in making anode of a dry cell?
Advertisements
उत्तर
(a) Carbon is the element 'E' which exists in three allotropic forms A, B and C.
(b) Buckminsterfullerene is the allotrope, A, of carbon in which the atoms are joined to form spherical molecules.
(c) Graphite is the allotrope, B, of carbon which is surrounded by three other carbon atoms to form a sheet like structure.
(d) Diamond is the allotrope, C, of carbon in which each atom is surrounded by four other carbon atoms to form a rigid structure.
(e) The allotrope C (Diamond) is used to make jewellery.
(f) The allotrope B (Graphite) is used in making anode of a dry cell.
APPEARS IN
संबंधित प्रश्न
Name the black substance of pencil. Will the current flow through the electrical circuit when we use the sharpened ends of the pencil to complete the circuit?
How does graphite act as a lubricant?
Fill in the following blank with suitable word:
The general formula CnH2n for cycloalkanes is the same as that of ...........
Compare the properties of ionic compounds and covalent compounds.
State any two uses of graphite.
One of the following contains a double bond as well as single bonds. This is:
(a) CO2
(b) O2
(c) C2H4
(d) C2H2
The electronic configurations of three elements X, Y and Z are as follows:
| X | 2, 4 |
| Y | 2, 7 |
| Z | 2, 1 |
(a) Which two elements will combine to form an ionic compound?
(b) Which two elements will react to form a covalent compound?
Give reasons for your choice.
Give the formulae of the chlorides of the elements X and Y having atomic numbers of 3 and 6 respectively. Will the properties of the two chlorides be similar or different? Explain your answer.
Complete the following:
In case of non-polar covalent bond, the covalent bond is formed in the ______ of atoms and shared electrons are ______ distributed. (corner, middle, equally, unequally)
In the formation of electrovalent compounds, electrons are transferred from one element to another. How are electrons involved in the formation of a covalent compound?
Explain the bonding in methane molecule using electron dot structure.
Which of the following is a common characteristic of a covalent compound?
Explain why carbon tetrachloride does not dissolve in water.
Complete the following activity.
Write the names of the hydrocarbons for the following structural formula.
(isobutylene, cyclohexane, propene, cyclohexene, cyclopentane, benzene, propyne, isobutane, propane)
| \[\begin{array}{cc} \phantom{..}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\ \phantom{..}|\phantom{....}|\phantom{....}|\\ \ce{H - C - C- C- H}\\ \phantom{.}|\phantom{....}|\phantom{....}|\\ \ce{H - C - H}\\ |\\\ce{H}\end{array}\] |
Give an example for each of the following statement.
Formation of coordinate covalent bond between NH3 ➝ BF3 molecules
Which of the following is the formula of Butanoic acid?
`"CH"_3 - "CH"_2 - "OH" overset("Alkaline""KMnO"_4 + "Heat")(->) "CH"_3 - "COOH"`
In the above given reaction, alkaline KMnO4 acts as
Write notes on the characteristics of covalent compounds.
Show the covalent bond formation in nitrogen molecule.
Explain dipole (polar) molecule by taking hydrogen chloride as an example.
