| 1. | Mg2X3 | 2. | MgX2 |
| 3. | Mg2X | 4. | Mg3X2 |
The incorrect match among the following is:
1. B < C < N < O (increasing first ionisation enthalpy)
2. I < Br < F < Cl (increasing electron gain enthalpy)
3. Li < Na < K < Rb (increasing metallic radius)
4. Al3+ < Mg2+ < Na+ <F- (increasing ionic size)