Question

Ruby, the gemstone
I. is aluminium oxide $\left(A{l}_2{O}_3\right)$.
II. contains $0.5-1\%C{r}^{3+}$ ions $\left(d^3\right)$.
III. $C{r}^{3+}$ ions are randomly distributed in positions normally occupied by $A{l}^{3+}$.
The true statement(s) is/are

• A. $I$ and $II$
• B. Only $III$
• C. $II$ and $III$
• D. $I,II$ and $III$

Answer 1

Answer: (A)

Correct answer is (a) $I$ and $II$