The two elements A and B have similar chemical properties and do not form solid Hydrogen carbonate but react with Nitrogen forming Nitrides.Elements A and B are:
Lithium and Magnesium
Explanation for the correct options:
(D) Lithium and Magnesium
Explanation for the incorrect options:
A. Sodium and Calcium
B. Cesium and Barium
C. Sodium and Rubidium
Hence option (D) is correct, Lithium and Magnesium have similar chemical properties and do not form solid Hydrogen carbonate but react with Nitrogen forming Nitrides.