The GATE Grind

GATE 2025 MT – Question 18

Materials Science and Non-Metallic Materials · Crystal structures and bonding · 1 mark · Multiple choice

The coordination number for an octahedral site in pure copper is ______.

  1. 4
  2. 6
  3. 8
  4. 12

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (B) 6

Explanation

An octahedral site is surrounded by six host atoms at the vertices of an octahedron. Therefore its coordination number is **6, B**. Copper atoms themselves have FCC nearest-neighbour coordination 12, but the question concerns the interstitial site.