The alkali metals form salt like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following order

The alkali metals form salt like hydrides by the direct synthesis at e

1.	The alkali metals form salt like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following order
Answer» NaH `gt` LIH `gt` KH `gt` RBH `gt` CsH LiH `gt` NaH `gt` KH `gt` RbH `gt` CsH CsH `gt` RbH `gt`KH `gt` NaH `gt` LiH KH `gt` NaH `gt` LiH `gt` CsH `gt` RbH. Solution :As the size of the ALKALI metal ION increases, lattice ENERGY decreases and hence, the stability of the corresponding metal hydride decreases.