Question

Atoms of elements A and B form Molecules Ax By and
Cyrstallises in hcp lattice. The element A occupy
1/2 of the tetrahedral voids. calculate x and y​

Answer 1

Answer:

Given that, atoms of B forms hcp lattice. So, the atoms at corners are shared by 6 unit cells. So, its contribution is  

6

1

​  

; Face centered atoms contribute  

2

1

​  

 and middle layer atoms contribute 1 each.

So, effective number of atoms in unit cell =  

6

1

​  

×12+  

2

1

​  

×2+1×3

=2+1+3=6

Number of tetrahedral voids =2× Number of atoms forming the lattice.

=2×6=12

So, number of atoms of A=  

3

2

​  

×12=8

Number of atoms of B=6

So, A:B⇒A:B

      8:6        4:3

So, formula is A  

4

​  

B  

3

​

hope it helps

thank u