Question

In a solid ab having the NaCl type structure. atoms occupy the corners of the cubic unit cell. if all the corners atoms along one of the axes are removed, then the resultant stoichiometry of the solid is :

• A. $A_8{B}_5$
• B. $AB$
• C. $A_3{B}_4$
• D. $A_3{B}_8$

Answer 1

The correct option is C $A_3{B}_4$

Accordag to structuror of Nacl-fice Here A Will orcupy 8 corners of cubie "unit cell which Will 1 contribute $\frac{1}{8}$ each to the cabe therefore $8\times \frac{1}{8}=1$

and 6 foce comer alome asele contribule $\frac{1}{2}$

$6\times \frac{1}{2}=3$

Some like $B$ - $B$. bect edce $c$.

$=1+12\times \frac{1}{4}-4$

SSo the formuln is $AR$ or $A_t{B}_4$

Nao we remoning all fice atom along the anis

So the number of atoms -removed from the

cube ire 2

So cmtribution of comer ahm $=8\times \frac{1}{8}=1$

& face $=4\times \frac{1}{2}=2$

therefore $=1+2=3$

$\text{Hence formule is}{A}_3{B}_4$

Correct Answer $-\underset{–}{C}$