A metal has a fcc lattice.The edge length of the unit cell is `404` pm ,the density of the metal is `2.72g cm^(-3)` . The molar mass of the metal is `(N_(A)`, Avorgadro's constant `=6.02xx10^(23)mol^(-1))`

Options

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

Answer

b

Explanation

we know
`d = (Z xx M)/(V xx N_(A))`
`2.72 = (4 xx M)/(6.02 xx 10^(23) xx (404 xx 10^(-10))^(3))`
`M = 27 g mol^(-1)`