Answer
$[(3*1.18*10^29)/(4*pi)]^{1/3}=1.41*10^{-10} m$
$2*1.41*10^{-10}=2.82*10^{-10}m$
Work Step by Step
Volume of sphere=(4*pi*r$^3$)/3.
Solve for r, which became [3*v/(4*pi)]$^{1/3}$.
The distance between two atomic center is twice the radius, multiply the r by 2.
