Question One

$($a$)$ What is the common name given to the following defects?

I. Point defects or missing atoms

II$.$ Line defects or rows of missing atoms

III. Area defects

$($b$)$ How do we describe crystalline solids and which types exist?

$[3]$

$($c$)$ Although there are only $7$ crystal systems or shapes, there are $14$ different crystal lattices, called Bravais Lattices. Name all the $14$ different lattices

$($d$)$ Describe the HCP and CCP close$-$packed crystal structures

$($e$)Al$ has a cep arrangement of atoms. The radius of $Al$ is $1\mathrm{.}301.$ Calculate the lattice parameter of the unit cell and the density of solid $Al($Ar is $26\mathrm{.}98)$

Question Two

$($a$)$ Show that $\frac{r}{r_a}$ is $0\mathrm{.}414$ for an octahedral crystal structure

$[2]$

$($b$)$ Describe the Wurtzite and Fluorite structures

$[4]$

$($c$)$ Explain and describe the trend in ionic radii across the $3^{rd}$ period down G$1$ and G$7[4]$

$($d$)$ Describe the CVD $($Lithium Niobate$)$ and CVT $($Magnetite$)$ methods

$6$

$($e$)$ Briefly explain the following terms

I. Intrinsic defects

$[3]$

II$.$ Extrinsic defects

$3$

Question Three

$($a$)$ Outline the procedure of the ceramic method

$[4]$

$($b$)$ Describe the preparation of Barium Titanate using the Precursor Method

$5$

$($c$)$ Which synthetic methods would be suitable for producing the following characteristics

I. A thin film of material

II$.$ A single crystal

III. A single crystal containing layers of different material with the same crystal structure

$[3]$