Question

Which of the following is not a Zachariasen's rule?

• A. Oxygen polyhedra share only corners
• B. The oxygen should link more than four glass forming atoms
• C. Three-dimensional network should form
• D. Co-ordination number of glass forming atom should be small

Hint:

Zachariasen's rules support an open random network. Oxygen polyhedra share corners, and coordination number of glass formers is small.

Answer 1

The Correct Option is B

Zachariasen proposed rules for the formation of oxide glasses. These rules explain how glass-forming oxides can form random three-dimensional networks. According to Zachariasen's rules, the coordination number of the glass-forming cation should be small. The oxygen polyhedra should share only corners, not edges or faces. A three-dimensional network should be formed. Also, an oxygen atom should not be linked to too many glass-forming atoms. In general, oxygen should link only a small number of glass-forming cations. The statement: \[ \text{The oxygen should link more than four glass forming atoms} \] is not a Zachariasen's rule. This is because linking oxygen to many glass-forming atoms would not produce the required open random network structure. Therefore, the correct answer is: \[ \text{The oxygen should link more than four glass forming atoms}. \]