Advertisements
Advertisements
प्रश्न
Define Anisotropy.
Advertisements
उत्तर
The ability of crystalline solids to change values of physical properties when measured in different directions is called anisotropy.
APPEARS IN
संबंधित प्रश्न
The major binding force in diamond is_______________ .
(a) Covalent bond
(b) Ionic bond
(c) Metallic bond
(d) Co-ordinate covalent bond
What is the covalency of nitrogen in N2O5?
Give an example each of a molecular solid and an ionic solid.
Explain the basis of similarities between metallic and ionic crystals.
Distinguish between crystalline solids and amorsphous solids.
Answer the following in one or two sentences.
A solid is hard, brittle and electrically nonconductor. Its melt conducts electricity. What type of solid is it?
Sodium crystallizes in bcc structure. If the edge length of unit cell is 4.3 × 10-8 cm, the radius of Na atom is ______.
Assertion: monoclinic sulphur is an example of a monoclinic crystal system
Reason: for a monoclinic system, a ≠ b ≠ c and α = γ = 90°, β ≠ 90°
The ionic radii of A+ and B− are 0.98 × 10−10 m and 1.81 × 10−10 m. The coordination number of each ion in AB is ______.
Give any three characteristics of ionic crystals.
Dry ice is an example of ____________.
Which among the following is NOT a polar molecular solid?
Which among the following is an example of network solid?
Solid X is a very hard electrical insulator in solid as well as in molten state. It melts at extremely high temperature. Solid X is a ____________.
Nature of binding forces present in carbon dioxide molecules in solid state are ____________.
Ionization enthalpy is lowest in ____________.
London forces are present in ____________.
MgO has the structure of NaCl. The coordination number of the ions in MgO is ____________.
Among solids, the highest melting point is exhibited by ____________.
Which of the following exists as covalent crystals in the solid state?
The major binding force of diamond, silicon and quartz is ____________.
Which one of the following forms a molecular solid when solidified?
Iodine molecules are held in the crystals lattice by ______.
NaCl type crystal (with coordination no. 6 : 6) can be converted into CsCl type crystal (with coordination no. 8 : 8) by applying ____________.
How many chloride ions are surrounding sodium ions in sodium chloride crystal?
An excess of potassium ions makes KCl crystals appear violet or lilac in colour since:
(i) some of the anionic sites are occupied by an unpaired electron.
(ii) some of the anionic sites are occupied by a pair of electrons.
(iii) there are vacancies at some anionic sites.
(iv) F-centres are created which impart colour to the crystals.
Which of the following exists as covalent crystals in the solid state?
A reddish-pink substance on heating gives off a vapour which condenses on the sides of the test tube and the substance turns blue. If on cooling water is added to the residue it turns to original colour. The substance is ______.
Quartz is which type of crystal?
