Diamond has face-centred cubic lattice. There are two atoms at `(0, 0, 0)` and `((a)/(4), (a)/(4), (a)/(4))` coordinates. The ratio of the carbon-carbon bond distance to the edge of the unit cell is

Options

A. `sqrt(3/16)`
B. `sqrt(1/4)`
C. `1/4`
D. `1/sqrt2`

Answer

A

Explanation

Carbon atoms are at corners and are at alternate corners.So from geometry
`sqrt3(a/2)1/2=2r`
So required ratio`=(2r)/a=sqrt3/4=sqrt(3/16)`