sblock Elements - Result Question 61
####12. $NaH$ is an example of
(2019 Main, 11 Jan I)
(a) metallic hydride
(b) electron-rich hydride
(c) saline hydride
(d) molecular hydride
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Answer:
Correct Answer: 12. (d)
Solution:
- $\stackrel{\oplus}{Na} \stackrel{\ominus}{H}$ is an example of ionic or saline hydride. These hydrides are formed when hydrogen combines with metals having less electronegativity and more electropositive character with respect to hydrogen.
Except Be and Mg, all $s$-block metals form saline hydrides.
Hydrides of $p$-block elements are covalent in nature, viz, electron deficient hydrides (by group-13 elements), electron-precise hydrides (by group-14 elements), and electron-rich hydrides (by group 15-17 elements). Hydrides of $d, f$-block metals are called interstitial or metallic hydrides.
