Total $=100$ Points

Time: $11$:$00$AM $-12$:$15$ PM

$1.$

$2.$ Calculate the diffusion coefficient of aluminum in gold at $827C,$ whereas the diffusion cocfficient aluminum in gold at $627C$ is $2\mathrm{.}0{10}^{-14}\frac{m^2}{s}.$ The activation energy for the diffusion of aluminum in gold is $1,930,06\frac{J}{m}ol.$

$(20$ points$)$

$19300$

$3.$ Calculate the number of vacancies $($per cubic meter$)$ at $300C$ of Copper whose atomic weight is $63\mathrm{.}54g\frac{m}{m}ol$ and density is $8\mathrm{.}96g\frac{m}{c}{m}^3.$ The equilibrium fraction of lattice sites that are vacant in copper at $300C$ is $3{10}^{-5}$

$(20$ points$)$

$4.$ A metal that has a density of $8\mathrm{.}37\frac{g}{c}{m}^3,$ atomic weight of $76\mathrm{.}3\frac{g}{m}ol$ and an energy for vacancy formation of $2\mathrm{.}22e\frac{V}{?}$ atom. Calculate the number of vacancies $(Nv)$ per cubic meter at $800C$ for.

$(20$ points$)$

$5.$ An alloy that consists of $84\mathrm{.}5$ weight percent Copper and $15\mathrm{.}5$ weight percent Silver. Calculate the composition of individual elements, in atomic percent? The atomic weight of silver is $107\mathrm{.}87g\frac{m}{m}ol.$

points$)$

$6.(20$ points$)$

$($i$)$ What is the unit of strain?

$($ii$)$ How many numbers of atoms present is face centered cubic and simple cubic unit cell

$($iii$)$ Two examples of crystalline and amorphous materials?

$($iv$)$ Why density of metal is higher than polymers?

$($v$)$ Which is more elastic, steel or rubber?

$($vi$)$ what is Hooks law?

$($vii$)$ what is the charge of an atom?