| Front | Cr and Al do not dissolve in concentrated nitric acid. |
| Back | due to the formation of a passive film of oxide on the surface |
| Tags | Group15 |
| Front | Group 18 elements exhibit very high ionization enthalpy. |
| Back | due to stable electronic configurations |
| Tags | Group18 |
| Front | Ammonia (NH3) acts as a Lewis base. |
| Back | due to the presence of one lone pair of electrons which it can donate and form linkage with metal ions |
| Tags | Group15 |