Na and Mg crystallise in body-centered cubic and face-centered cubic crystals respectively, then the number of atoms of Na and Mg present in the unit cell of their respective crystals is :
Correct answer: D. 2 and 4
- A. 4 and 2
- B. 9 and 14
- C. 14 and 9
- D. 2 and 4
Explanation
The correct option is D (2 and 4 ) The body centered cubic cell consistes of 8 atoms at the corners and one atom at the centre. ∴n = (8/8)+1= 2. The face centered cell consists of 8 atoms at the eight corners and one atom at each of the six faces. This atom at the faces is shared by two unit cells. ∴n = 8/8 + (6/2) = 4
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Crystal Lattice
A crystal lattice is the regular three-dimensional arrangement of particles in a crystalline solid. The content includes lattice points, unit cells, coordination number, packing patterns, and the differences among ionic, metallic, molecular and covalent network crystals, which should not be confused with amorphous solids.
Practise Solids
357 free Solids MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Crystal Lattice questions
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centered cubic unit cell are _ respectively :
Ice crystallises in a hexagonal lattice having volume of the unit cell as 132 x 10^-24 cm. If density is 0.92 gcm-3 at a given temperature, then number of H2O molecules per unit cell is:
Regarding graphite the following information is available.
A solid compound contains X, Y and Z atoms in a cubic lattice with X atoms occupying the corners, Y atoms in the body centred positions and Z atoms at the centre of the faces of the unit cell. What is the empirical formula of the compound?
An element 'A' has face-centred cubic structure with edge length equal to 361 pm. The apparent radius of atom 'A' is :
Sodium (Na = 23) crystallizes in body-centered cubic arrangement with the interfacial separation between the atoms at the edge 53.6pm. The density of sodium crystal is: