A metal has an fcc latticed.The edge length of the unit cell is `404` pm .The density of the metal is `2.72 g//cm^(-3)` .The molar mass of the metal is
`(N_(A)` Avogadro's constant `= 6.2 xx 10^(23) mol^(-1))`

Options

A. ` 40 g mol^(-1)`
B. `30 g mol^(-1)`
C. `27 g mol^(-1)`
D. `20 g mol^(-1)`

Explanation

Density , ` p = ( Z xx M)/(a^(3) xx N_(A) xx 10^(-30))`
` therefore 2.72 = ( 4 xx M)/(( 404)^(3) xx ( 6.02 xx 10^(23)) xx 10^(-30))`
`or M = ( 2.72 xx (404)^(3) xx 6.02 xx 10^(23) xx 10^(-30))/4`
` = 27 g mol^(-1)`