Experiment shows that Nickel oxide has the formula Ni_0.96.O_1.00. What fraction of Nickel exists as of Ni²⁺ and Ni³+ ions?

Why are solids rigid?

Silver crystallines in fcc lattice. If edge length of the cell is 4.07 x 10^-8 em and density is 10.5 g cm^-3. Calculate the atomic mass of silver

If NaCI is doped with 10^-3 mol % of SrCl₂ What is the concentration of cation valencies?

Why are solids incompressible?

Classify the following solids in different categories based on the nature of intermolecular force operating in them: Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphide, graphite, rubidium, argon, silicon carbide.

What is the formula of a compound in which the element Y forms ccp lattice and atoms of X occupy 2/3^rd of tetrahedral voids?

Calculate the number of unit cells in 8.1 g of aluminium, if it crystallises in a face centered cubic structure. (Atomic mass of AI = 27 g mol^-1).

Inspite of long range order in the arrangement of particles, why are the crystals usually not perfect?

Examine the given defective crystal:

X+	Y-	X+	Y-	X+
Y-	O		X+
X+		X+	O	X+
Y-	X+	Y-	X+	Y-

Answer the following questions
(i) Is the above defect stoichiometric or non-stoichiometric?
(ii) What are such defects called? Give an example of the compound which shows this type of defect.

ZnO turns yellow on heating. Why?

(i) What change occurs when AgCl is doped with CdCI₂?
(ii) What type of semiconductor is produced when silicon is doped with boron?

How do the spacings of the three planes (100), (101) and (111) of simple cubic lattice vary?

Diffraction angle 2θ equal to 14.8^o for a crystal having interplanar distance in the crystal is 0.400 nm when second order diffraction was observed. Calculate the wavelength of X-ray used.

A metallic element exists as a cubic lattice. Each edge of the unit cell is 2.88\(\mathring { A } \). The density of the metal is 7.20 g cm^-3. How many unit cells there will be in 100g of the metal?