| 1. | Both Sc3+ and Zn2+ ions are colourless and form white compounds |
| 2. | In the case of Sc, 3d orbitals are partially filled but in Zn, these are fully filled. |
| 3. | The last electron is assumed to be added to the 4s level in the case of Zn |
| 4. | Both Sc and Zn do not exhibit variable oxidation states. |
| 1. | |
| 2. | \(\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{NH}_2+\mathrm{HNO}_2 \rightarrow \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}+\mathrm{N}_2 \) |
| 3. | \(\mathrm{CH}_3 \mathrm{NH}_2+\mathrm{C}_6 \mathrm{H}_5 \mathrm{SO}_2 \mathrm{Cl} \rightarrow \mathrm{CH}_3 \mathrm{NHSO}_2 \mathrm{C}_6 \mathrm{H}_5 \) |
| 4. | \(\left(\mathrm{CH}_3\right)_2 \mathrm{NH}+\mathrm{NaNO}_2+\mathrm{HCl} \rightarrow\left(\mathrm{CH}_3\right)_2 \mathrm{~N}-\mathrm{N}=\mathrm{O} \) |