The correct option for the number of body centred unit cells in all $14$ types of Bravais lattice unit cells is :
- 7
- 5
- 2
- 3
The Correct Option is D
Solution and Explanation
Top Questions on Unit Cells
- Find the radius of a BCC molecule having an edge length of \( 2.0 \times 10^{-11} \) m.
- MHT CET - 2025
- Chemistry
- Unit Cells
If the total volume of a simple cubic unit cell is 6.817 × 10-23 cm3, what is the volume occupied by particles in the unit cell?
- MHT CET - 2025
- Chemistry
- Unit Cells
- The density of a face-centered cubic (FCC) crystal is:
- MHT CET - 2024
- Chemistry
- Unit Cells
- What is the coordination number in a Hexagonal Close-Packed (hcp) structure?
- MHT CET - 2024
- Chemistry
- Unit Cells
- Which of the following statements is incorrect for antibiotics?
- JEE Main - 2023
- Chemistry
- Unit Cells
Questions Asked in NEET exam
- Which of the following organisms cannot fix nitrogen? A. Azotobacter
B. Oscillatoria
C. Anabaena
D. Volvox
E. Nostoc
Choose the correct answer from the options given below:- NEET (UG) - 2025
- Nitrogen Fixation
- Which of the following are paramagnetic?
A. [NiCl$_4$]$^{2-}$
B. Ni(CO)$_4$
C. [Ni(CN)$_4$]$^{2-}$
D. [Ni(H$_2$O)$_6$]$^{2+}$
E. Ni(PPh$_3$)$_4$
Choose the correct answer from the options given below:- NEET (UG) - 2025
- Coordination chemistry
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): A typical unfertilized, angiosperm embryo sac at maturity is 8-nucleate and 7-celled.
Reason (R): The egg apparatus has 2 polar nuclei.In the light of the above statements, choose the correct answer from the options given below:
- NEET (UG) - 2025
- Angiosperms
- A ball of mass 0.5 kg is dropped from a height of 10 m. The ball hits the ground and rises to a height of 1.5 m. The impulse imparted to the ball during its collision with the ground is : (Take \(g = 9.8 \, \text{m/s}^2\))
- NEET (UG) - 2025
- Collision and Impulse
- Consider the diameter of a spherical object being measured with the help of a Vernier Callipers. Suppose its 10 Vernier Scale Divisions (V.S.D.) are equal to its 9 Main Scale Divisions (M.S.D.). The least count in the M.S. is 0.1 cm and the zero of V.S. is at -0.1 cm when the jaws of Vernier callipers are closed. If the main scale reading for the diameter is \(M = 5\) cm and the number of coinciding vernier division is 8, the measured diameter after zero error correction, is:
- NEET (UG) - 2025
- Measurement of length
Concepts Used:
Unit Cells
The smallest portion of a crystal lattice which repeats in different directions to form the entire lattice is known as Unit cell.
The characteristics of a unit cell are:
- The dimensions are measured along the three edges, a, b and c. These edges can form different angles, they may be mutually perpendicular or may not.
- The angles held by the edges are α (between b and c) β (between a and c) and γ (between a and b).
Therefore, a unit cell is characterised by six parameters such as a, b, c and α, β, γ.
Types of Unit Cell:
Numerous unit cells together make a crystal lattice. Constituent particles like atoms, molecules are also present. Each lattice point is occupied by one such particle.
- Primitive Unit Cells: In a primitive unit cell constituent particles are present only on the corner positions of a unit cell.
- Centred Unit Cells: A centred unit cell contains one or more constituent particles which are present at positions besides the corners.
- Body-Centered Unit Cell: Such a unit cell contains one constituent particle (atom, molecule or ion) at its body-centre as well as its every corners.
- Face Centered Unit Cell: Such a unit cell contains one constituent particle present at the centre of each face, as well as its corners.
- End-Centred Unit Cells: In such a unit cell, one constituent particle is present at the centre of any two opposite faces, as well as its corners.