Solid State Tes...

If silver iodide crystallizes in a zinc blendek structure with $$I^-$$ ions forming the lattice, then the fraction of the tetrahedral voids occupied by $$Ag^+$$ ions will be:

Crystals are formed by ions, atoms, and molecules having an internal pattern that is ___________ and ___________.

Which one of the following has a different crystal lattice from those of the rest?

In a crystal, atoms are located at the position of:

An element occurs in two crystalline forms $$\alpha$$ and $$\beta$$. The $$\alpha$$-form a fcc arrangement with $$a=3.68$$ $$\mathring{A}$$ and the $$\beta$$-form has a bcc arrangement with $$a=2.92 \mathring { A}$$. Calculate the ratio of their densities. 

In a face centred cubic arrangement of $$A$$ and $$B$$ atoms when $$A$$ atoms are at the corner of the unit cell and $$B$$ atoms of the face centres. One of the $$A$$ atom is missing from one corner in unit cell. The simplest formula of compound is:

The pyknometer density of $$NaCl$$ crystal is $$2.165\times { 10 }^{ 3 }kg\quad { m }^{ -3 }$$ while its X-rays density is $$2.178\times { 10 }^{ 3 }kg\quad { m }^{ -3 }$$. The fraction of the unoccupied sites in $$NaCl$$ crystal is:

When heated above $$ 916^o C , $$ iron changes its crystal structure from bcc to ccp structure without any change in the radius of atom. The ratio of density of the crystal before heating and after heating is :

Which among the following metals crystallise as a simple cube?

Which of the following defect is seen in $$FeO$$?