In non stoichiometric defects ratio of cation and anion is not same that is represented by chemical ideal formula, this is due to variable oxidation nos of cation. Transition elements show variable oxidation nos.
2.
$$AB;$$ crystallizes in a body centred cubic lattice with edge length $$'a'$$ equal to $$387\,pm.$$ The distance between two oppositely charged ions in the lattice is
In antiferromagnetic substances, their domains are oppositely oriented and cancel out each other's magnetic moment.
4.
Solid $$X$$ is a very hard solid which is electrical insulator in solid as well as in molten state and has extremely high melting point. What type of solid is it ?
The given properties are shown by covalent solids which are network solids and very hard with high melting point. They are insulators in solid as well as in molten state.
5.
The edge length of unit cell of a metal having molecular weight $$75\,g/mol$$ is $$5\mathop {\text{A}}\limits^{\text{o}} $$ which crystallizes in cubic lattice. If the density is $$2g/cc$$ then find the radius of metal $$atom.\left( {{N_A} = 6 \times {{10}^{23}}} \right).$$ Given the answer in $$pm.$$
6.
$$CsBr$$ crystallises in a body centered cubic lattice. The unit cell length is $$436.6\,pm.$$ Given that the atomic mass of $$Cs = 133$$ and that of $$Br = 80\,amu$$ and Avogadro number being $$6.02 \times {10^{23}}\,mo{l^{ - 1}},$$ the density of $$CsBr$$ is
$$\eqalign{
& AB = \frac{{\sqrt 3 a}}{2}\,\,{\text{(nearest)}} \cr
& AC = a\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\text{(next - nearest)}} \cr
& CD = \sqrt 2 a\,\,\,{\text{(next - next - nearest)}} \cr} $$
10.
A metal $$X$$ crystallises in a face-centred cubic arrangement with the edge length $$862\,pm.$$ What is the shortest separation of any two nuclei of the atom ?