Solid State (Class 12th) Flashcards
(28 cards)
packing efficiency of simple cubic unit cell
52.4
packing efficiency of FCC
74
packing efficiency of BCC
68
packing efficiency of HCP - 3D
74
packing efficiency of HCP - 2D
90.4
packing efficiency of Square Close Packing
78.4
packing efficiency of diamond
34
relation between edge length and radius in simple cubic unit cell
a=2r,d=a
relation between edge length and radius in FCC
a=2root2r d=a/root2
relation between edge length and radius in BCC
a=4r/√3 d=√t3 a /2
Density of unit cell (g/cm^3)
z*M/ Avag. no. * a^3
z(no of atoms in lattice) value for FCC,BCC and ECC
4,2,2
z value for HCP-3d
6
z value for diamond
8
Nacl type, Zns type, CaF2 type , Na2O type z=
4
CsCl z=
1
(sum of radius of cation and anion of NaCl) * 2
a
(sum of radius of cation and anion of CsCl) * 2
√3 a
what is radius ratio?
radius of cation/ radius of anion
significance of radius ratio
directly proportional to cation radius and coordination number
what are the ranges of radius ratio,C.N and type of void
- 155 - 0.225 (3) triangular
- 255- 0.414 (4) tetrahedral
- 414 - 0.732 (6) octahedral
- 732 - 1 (8) cubic
eg of cn = 3
triangular void - b2o3
eg of cn = 4
ZnS CuCl CuBr CuI HgS
eg of cn = 6
NaCl, MgO, CaO
