Question

At a certain temperature and pressure an element has the simple body-centred cubic unit cell, depicted below. The corresponding atomic radius is 1.689 Å and the density is 9.798 g cm^-3. Calculate (and enter) the atomic mass for this element (in amu).

Answer 1

The given problem will be solved by using the formula 8- Zxm - i) VD NAXQ3 where Pa density of element = 9.798 gan's Z- atom contribution = 2 (For body-centered Cubic enit cell) M = atomic mass of element = ? NA = 6.022 x 10??meen a= edge length Fog Bcc., edge length (a) and atomic radius Cr) are related as 53a=40 a = 4x = 4X10689 A° - 3.90 4° = 3.90x16cm . 53 1.732 edge length Plugging the values in equ ci) we get 9.7989cms 2xM VV 6.022 X16??mol-'x (3.90 x16 eem) 9.7989cms - 2xM 6,022 X(3.90 x 15 mot cm3 M = 9.798 gem? x 6.022 X (3.90) x 10 most cha M= 1759 msk = 17same [samu = 39 mee]