An element ( x ) (atomic wt. ( =125 ) ) crystallises in simple cubic structure. If diameter of the largest atom which can be placed without disturbing unit cell is 366 pm. Find the density of pure element ( X ) in
( mathrm{gm} / mathrm{cm}^{3} )

For Simple cubic unit cell
( 2 r=a )
( r=r a d i u s ) of atoms ( X )
If Radius of the largest atom that can be
placed ( =mathrm{R} )
( 2 R=366 p m )
( 2 r+2 R=a sqrt{3} )
( a+366=a(sqrt{3}-1) )
( 366=a(sqrt{3}-1) )
( begin{aligned} a &=frac{366}{0.732} &=500 mathrm{pm} end{aligned} )
Answer: 0500