1. | The oxidation state and coordination number (or covalency) of \(\mathrm{Al}\) in\( \left[\mathrm{AlCl}\left(\mathrm{H}_2 \mathrm{O}\right)_5\right]^{2+} \) are +3 and 6, respectively. |
2. | \(\mathrm{Na}_2 \mathrm{O}\) is a basic oxide and \(\mathrm{Cl}_2 \mathrm{O}_7\) is an acidic oxide |
3. | The following four species are called isoelectronic species: \( \mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Na}^{+} \mathrm{and}~ \mathrm{Mg}^{2+}\) |
4. | Among the four species \(\mathrm{Mg}, \mathrm{Al}, \mathrm{Mg}^{2+}\) and \(\mathrm{A l^{3+},}\) the smallest one is \(\mathrm{Al}.\) |
1. | X is an alkali metal and Y is an alkaline earth metal. |
2. | X is an alkaline earth metal and Y is an alkali metal. |
3. | Both X and Y are alkali metals. |
4. | Both X and Y are alkaline earth metals. |
1. | C < N < F < O | 2. | C < N < O < F |
3. | C < O < N < F | 4. | C < F < N < O |
For the second-period elements, the correct increasing order of first ionisation enthalpy is:
1. | Li < Be < B < C < O < N < F < Ne |
2. | Li < Be < B < C < N < O < F < Ne |
3. | Li < B < Be < C < O < N < F < Ne |
4. | Li < B < Be < C < N < O < F < Ne |