Solid State Tes...

The packing efficiency of the two dimensional square unit cell shown below is  :

Lithium borohydride crystallizes in an orthorhombic system with $$4$$ molecules per unit cell. The unit cell dimensions are $$a=6.8\:\mathring{A}$$, $$b=4.4\:\mathring{A}$$ and $$c=7.2\:\mathring{A}$$. If the molar mass is 

CsBr crystallizes in a body-centred cubic lattice of unit cell edge length $$436.6$$ pm. Atomic masses of Cs and Br are $$133$$ amu and $$80$$ amu respectively. The density (in g cm$$^{-3}$$) of CsBr is :

The pattern of successive layers of ccp arrangement can be designated as:

Absorption of photons by crystal

Metallic gold crystallises in fcc lattice. The edge length of the cubic unit cell is $$4.07$$ $$\mathring A$$. What is the density (in g cm$$^{-3}$$) of gold?

The density of solid argon is $$1.65$$ g mL$$^{-1}$$ at $$-233^\circ C$$. If the argon atom is assumed to be the sphere of radius $$1.54\times10^{-8}$$ cm, what percentage of solid argon is apparently empty space? 

An element (atomic mass $$= 100\ g / mol$$) having bcc structure has unit cell edge $$400\ pm$$. Then, density of the element is:

What is not a type of crystal?

Select the correct statement(s) about cubic structure of diamond.
1. Effective number of atoms present in a diamond cubic cell is $$8$$.
2. Each carbon is surrounded by four more carbon atoms.
3. Atomic radius of carbon is $$\displaystyle \frac{\sqrt{3}\times a}{8}$$, where a is edge length of cube.
4. Approximate packing fraction of unit cell is $$\displaystyle \frac{\sqrt{3}\times \pi }{16}$$.