(a) Find the angle between adjacent nearest-neighbor bonds in the silicon lattice. Recall that each silicon atom...

(a) Find the angle θ between adjacent nearest-neighbor bonds in the silicon lattice. Recall that each silicon atom is bonded to four of its nearest neighbors. The four neighbors form a regular tetrahedron – a pyramid whose sides and base are equilateral triangles.
(b) Find the bond length, given that the atoms at the corners of the tetrahedron are 388 pm apart.