In between the metals A and B, both form oxide but B also forms nitride, when both are heated in air. A and B are respectively

In between the metals A and B, both form oxide but B also forms nitrid

1.	In between the metals A and B, both form oxide but B also forms nitride, when both are heated in air. A and B are respectively
Answer» `Cs, K` `MG, CA` `Li, NA` `K, Li` ANSWER :D