The radius of a calcium ion () is and that of an oxide ion () is . Based on these values, the predic — Solid State Chemistry Question
Question
The radius of a calcium ion ($Ca^{2+}$) is $94\text{ pm}$ and that of an oxide ion ($O^{2-}$) is $146\text{ pm}$. Based on these values, the predicted crystal structure geometry of calcium oxide ($CaO$) will be:
Answer: B
💡 Solution & Explanation
Radius ratio $\frac{r_{Ca^{2+}}}{r_{O^{2-}}} = \frac{94}{146} \approx 0.644$. Because this value lies in the range $0.414 \le \frac{r_+}{r_-} < 0.732$, the structure will have an octahedral arrangement with a coordination number of 6.
💬Ask on WhatsApp →
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes