Calculate the distance between (111) planes in a crystal of calcium. Repeat the calculation for (222) planes. Which palnes are closer ? (a = 0.556 nm)

Explanation

`d=a/(sqrt(h^2+k^2+l^2))`
`d_111=0.556/(sqrt(1^2+1^2+1^2))=0.556/sqrt3`=0.321 nm
`d_222=0.556/(sqrt(2^2+2^2+2^2))=0.556/sqrt12`=0.161 nm
Thus (222) planes are closer and their distance of separation is half of that of (111) planes