To get a$\mathrm{n}-$type semiconductor, the impurity to be added to silicon should have which of the following number of valence electrons?

 

Doping of silicon with boron leads to_______.

In a crystal the atoms are located at the position of ________.       

Suppose the mass of a single $\mathrm{Ag}$ atom is $‘\mathrm{m}’$. $\mathrm{Ag}$ metal crystallizes in $\mathrm{fcc}$ lattice with unit cell of length $‘\mathrm{a}’$. The density of $\mathrm{Ag}$ metal in terms of $‘\mathrm{a}’$and $\text{'}\mathrm{m}’$ is______.

Volume occupied by single $\mathrm{CsCl}$ ion pair in a crystal is ${\mathrm{7.014\times 10}}^{\mathrm{-23}} {\mathrm{cm}}^{\mathrm{3}}$. The smallest $\mathrm{Cs}-\mathrm{Cs}$ Internuclear distance is equal to length of the side of the cube corresponding to volume of one $\mathrm{CsCl}$ ion pair. The smallest $\mathrm{Cs}\text{ to} \mathrm{Cs}$ internuclear distance is nearly_______.

A crystalline solid ${\mathrm{XY}}_3$ has $\mathrm{ccp}$ arrangement for its element $\mathrm{Y}.$ $\mathrm{X}$ occupies______.