Question

If the radius of octahedral void is $r$ and radius of the atoms in close packing is $R$, then the relation between $r$ and $R$ is:

• A. $r=0.732R$
• B. $r=0.414R$
• C. $r=0.98R$
• D. $r=0.225R$

Answer 1

The correct option is B $r=0.414R$

In the triangle ABC,
$B{C}^2=A{B}^2+A{C}^2$
$(2R{)}^2=(R+r{)}^2+(R+r{)}^2$

$\sqrt{2}R=R+r$,

$r=0.414R$