Question

An element $A$ and $B$ constitute $BCC$ type crystalline structure. Element $A$ occupies body centred positive and $B$ is at the corners of cube. What is the formula of the co-ordination number of $A$ and $B$?

Answer 1

The body centered crystalline structure (BCC), atoms are present on corners of the cubic lattice as well as on the body center of cube.

Now, $B$ is present on the corners of the cube. So, effective number of atoms of $B$ in the crystal $=\frac{1}{2}\times 2=1$

Number of atoms of $A$ present $=1$

So, formula of the compound is $AB$