🧪 Chemistry · Solid State · NEET & JEE

Copper (atomic mass 63.5 g/mol) crystallises in FCC with an atomic radius of 128 pm. Its approximate density is:

Answer: 8.9 g/cm³.

A 4.5 g/cm³
B 6.2 g/cm³
C 7.4 g/cm³
D 8.9 g/cm³

Correct answer: D. 8.9 g/cm³

Explanation: For FCC, a = 2sqrt2 r = 362 pm; d = (4 x 63.5)/(6.022 x 10²³ x (3.62 x 10^-8)³) = 8.9 g/cm³.

The three cubic unit cells: Simple Cubic has atoms only at corners; Body-Centred adds one atom at the centre; Face-Centred adds one atom at the centre of each of the 6 faces, giving the highest packing efficiency.

Concept context

Explore the ordered world of crystalline solids: unit cells, packing, defects, and how structure determines electrical and magnetic properties.

Read the full Solid State notes →

Copper (atomic mass 63.5 g/mol) crystallises in FCC with an atomic radius of 128 pm. Its approximate density is:

Concept context

More Solid State questions