Advertisements
Advertisements
Question
How many lattice points are there in one unit cell of the following lattice?
Face-centred cubic
Advertisements
Solution
Lattice points in an fcc lattice = 8 corners + 6 face centres
= 14
No. of particles per unit cell = `(8 xx 1/8) + (6 xx 1/2)`
No. of particles per unit cell = 4
RELATED QUESTIONS
A compound forms hexagonal close-packed structure. What is the total number of voids in 0.5 mol of it? How many of these are tetrahedral voids?
A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound? What are the coordination numbers of P and Q?
Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 125 pm.
- What is the length of the side of the unit cell?
- How many unit cells are there in 1.00 cm3 of aluminium?
The arrangement ABC ABC.... is referred to as ____________.
What is the coordination number in a square close packed structure in two dimensions?
Match the type of packing given in Column I with the items given in Column II.
| Column I | Column II |
| (i) Square close packing in two dimensions |
(a) Triangular voids |
| (ii) Hexagonal close packing in two dimensions |
(b) Pattern of spheres is repeated in every fourth layer |
| (iii) Hexagonal close packing in three dimensions |
(c) Coordination number 4 |
| (iv) Cubic close packing in three dimensions |
(d) Pattern of sphere is repeated in alternate layers |
With the help of a labelled diagram show that there are four octahedral voids per unit cell in a cubic close packed structure.
How can you best describe the elongated octahedral structure of blue vitriol, CuSO4.5H2O?
In the SF4 molecule, there are:
The crystal system of a compound with unit cell dimensions a = 0.387, b = 0.387 and c = 0.504 nm and α = β = 90° and ϒ = 120° is
Total no. of voids in 0.5 mole of a compound forming hexagonal closed packed structure are:-
The packing efficiency of the two dimensional square unit cell shown below is:
Co-ordination number of sodium ion Na+ in Nacl is:-
The number of tetrahedral and octahedral voids in a CCP array of 100 atoms are respectively:
The right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell is ______.
The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites in AxB. The value of x is ______. (Integer answer)
