In a two -dimensional hexagonal close-packed layer.
(i) each sphere is surrounded by six sphere
(ii) each sphere is surrounded by six voids
(iii)each void is surrounded by three spheres
(iv) there are on an average two voids belonging to each sphere

An octahedral void is surrounded by how many spheres ?

In planar square close packing , each sphere is surrounded by ______.

Which of the following statement is correct for a closet packed structure? (i) Each tetrahedral void is surrounded by 4 spheres and each sphere is surrounded by 8 tetrahedral voids. (ii) Each octahedral voids is surrounded by 6 spherus and each sphere is surrounded by 6 octahedral voids. (iii) The number of tetrahedral voids in a closest-packed arrangement is twice the number of spheres. (iv) The number of octahedral voids in a closest-packed arrangement is equal to the number of spheres.

(A) In close packing of spheres a tetrahedral void is surrounded by four spheres whereas an octahedral void is surrounded by six spheres. (R) A tetrahedral void has a tetrahedral shape whereas an octahedral void has an octa-hedral shape.

In a hexagonal closest packing in two layers one above the other, the coordination number of each sphere will be