The Solid State

Manganese is paramagnetic in nature

The coordination number of a molecule is referred to as the number of ions of the other charge surrounding the ion of the opposite charge. In the case of sodium chloride we have sodium ions placed and there are chloride ions surrounding each of the sodium ions. In the case of the ratio is and as a result there are sodium ions surrounding the chloride ion and vice versa.
In case of the periodic table we are well aware that as we move down the group then the size of the cation increases and as a result of the increase in the number of the shell as we move down. Thus we find that the size of the ion increases and hence caesium has a very large size compared to that of sodium. Hence there is a change in structure: the cesium ions do not form a lattice similar to that of sodium but rather we find that it occupies the centre of the cube that there are chloride ions surrounding it. Also as the ratio of is also as that of sodium hence we find that the coordination number remains as in this case.
Hence the answer to this question is that the coordination number of cesium in cesium chloride is .

Answer (c) copper

Some covalent solids like (quartz), , diamond and graphite have very high melting points .

A solid with low melting point and a poor conductor of heat and electricity is a molecular solid.

Radius ratio 0.32 lies in the range 0.225- 0.414 thus, C.N. = 4.

Number of ions= \underset{\text{(at corners)}}{ {\frac{1}{8} \times 8 + }} \underset{\text{(at face centres)}}{ {\frac{1}{2} \times 6 = 4 }}
Number of ions = \underset{\text{(atbody centre)}}{ {1 + }} \underset{\text{(at edge centres)}}{ {12 \times \frac{1}{4} = 4 }}

For
=848.4 pm

In order to maintain electrical neutrality, the number of missing cations and anions are equal in Schottky defect

The body-centered cubic (bcc) lattice has a vacant space of 32\%, which is the fraction of the total volume that is not occupied by atoms in the structure. Thus, the correct answer is Option (D).