Question

Metal hydrides are ionic, covalent or molecular in nature.
Among LiH, NaH, RbH, CsH, the correct order of increasing
ionic character is
(a) LiH > NaH > CsH > KH >RbH
(b) LiH < NaH < KH < RbH < CsH
(c) RbH > CsH > NaH > KH > LiH
(d) NaH > CsH > RbH > LiH > KH

Answer 1

Answer:

according to fajan s rules, size of the cation increases ionic character increases. so that option b is correct

Answer 2

LiH < NaH < KH < RbH < CsH is the correct order of increasing ionic character.

Explanation:

• The metal hydrides can be both ionic or covalent.

• But the alkali metals are strongly metallic, so their hydrides are generally ionic, although some shows partial covalent character.

• The covalency of the molecule increase as the central atom decrease in size.

• This is because the decrease in size of the central atoms make the pull of bonding atoms much stronger.

• According to Fajhan's rule, the size of the cations increase down a group.

• And also, the increase in size of an atom increases the ionicity of the molecules formed.

• Ceasium being lowest down tye group has most ionic character, followed by Rubidium, potassium, sodium and lithium respectively.

• Lithium hydride is more or less covalent.

For more information about Fajhan's rule,

https://brainly.in/question/11556292

Explain the covalent character of lithium chloride using fajans rule

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State and explain fajan's rule - Brainly.in