Question

In a cubic lattice if atoms are present only at all the corners and alternate face ` centres then the packing efficiency will be `​

Answer 1

Answer:

46%

Explanation:

For corners, z=1/8 x 8=1 z

For alternate face centres, z=3 x 1/2= 3/2

so, z= 1+3/2=5/2

Now, P.E= (z x 4/3nr^3) / a^3      (here n= pie)

here, a=4/root2r^3

Putting the values in the formula of packing efficiency above we get (in percentage) as 46%