Question
17. The alkali metals from salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following orders ? [AIPMT (Prelims)-2008] (1) LiH > NaH > KH > RbH > CsH (2) CsH > RbH > KH > NaH > LiH (3) KH > NaH > LiH > CsH > RbH (4) NaH > LiH > KH > RbH > CsH