Looking for classes? Ksquare Career Institute, Bengaluru →
Cubic unit cells
Appears in
Concepts tested here
- FCC radius-edge relation 2
- Body diagonal of a cube
All Questions
2015 AIPMT-I 1 question
-
A given metal crystallizes out with a cubic structure having edge length of 361 pm. If there are four metal atoms in one unit cell, what is the radius of one atom?Z = 4 means an fcc unit cell, where $r = \frac{a}{2\sqrt{2}}$.
$r = \frac{361}{2\sqrt{2}} \approx 127.6$ pm ≈ 127 pm
2014 AIPMT 1 question
-
If a is the length of the side of a cube, the distance between the body centered atom and one corner atom in the cube will be:The body-centred atom lies at the middle of the body diagonal (length $\sqrt3a$).
Distance from the centre to a corner $= \frac{\sqrt3a}{2}$
2012 AIPMT-PRE 1 question
-
A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is:In an fcc lattice the atoms touch along the face diagonal: $\sqrt2a = 4r$
Diameter $= 2r = \frac{\sqrt2a}{2} = \frac{a}{\sqrt2}$
$2r = \frac{408}{1.414} = 288$ pm