Define radius ratio. What is the value of radius ratio for octahedral geometry ?

Explanation

### Step-by-Step Solution:

**Step 1: Define Radius Ratio**
The radius ratio is defined as the ratio of the radius of a cation (the positively charged ion) to the radius of an anion (the negatively charged ion). Mathematically, it can be expressed as:
\[ \text{Radius Ratio} = \frac{r_c^+}{r_a^-} \]
where \( r_c^+ \) is the radius of the cation and \( r_a^- \) is the radius of the anion.
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