Question

For an ionic crystal of general formula AX and coordination number 6, the value of radius ratio will be ______.

Options

• greater than 0.73

• in between 0.73 and 0.41

• in between 0.41 and 0.22

• less than 0.22

Answer 1

For an ionic crystal of general formula AX and coordination number 6, the value of radius ratio will be in between 0.73 and 0.41.

Explanation:

For an ionic crystal with coordination number 6 (typically octahedral geometry), the radius ratio `r_+/r_−`​ lies between 0.414 and 0.732.

This range allows the cation to fit perfectly into the octahedral void, maintaining stability of the structure.